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Supplemental lecture: Urbanization and development — Transcript

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  1. 0:28recording
  2. 0:53right let's go ahead and start good
  3. 0:56morning good afternoon good evening
  4. 0:58wherever you are in the world
  5. 1:00and welcome to all to this the the last
  6. 1:03actual uh lecture in the stag virtual
  7. 1:06course on key concepts in macro
  8. 1:08development
  9. 1:10today's lecture is a supplemental
  10. 1:12lecture we're really delighted to have
  11. 1:14klaus desmond here to talk about
  12. 1:16urbanization
  13. 1:17and development it's um wonderful of you
  14. 1:20to join klaus
  15. 1:22and this is our 20th lecture
  16. 1:25it is um really wonderful to see so many
  17. 1:28people
  18. 1:29who have stuck with us throughout and
  19. 1:31i'm delighted to welcome everyone
  20. 1:34um i'd like to give special thanks
  21. 1:36before we begin
  22. 1:38to the team from cepr which has made it
  23. 1:42possible to put together
  24. 1:43this lecture series and has done the
  25. 1:45work behind the scenes
  26. 1:47um keeping material up on the website
  27. 1:50we're
  28. 1:50loading the recordings onto youtube so
  29. 1:53i'd particularly like to
  30. 1:54single out mandy chan christy mcneil
  31. 1:58lauren waring
  32. 1:59and nadine clark who've done an amazing
  33. 2:02job and made this
  34. 2:03and made this work the
  35. 2:06the course is part of the steg program
  36. 2:08and as we've said many times before and
  37. 2:10at the risk of boring those of you who
  38. 2:12are now hearing this for the 20th time
  39. 2:14steg is a research program steg stands
  40. 2:17for structural transformation
  41. 2:18and economic growth it's a research
  42. 2:21program
  43. 2:22funded by the united kingdom's foreign
  44. 2:24commonwealth
  45. 2:25and development office as part of the uk
  46. 2:288 effort it's managed by cepr in london
  47. 2:32and we've just been really very
  48. 2:35fortunate to find
  49. 2:36colleagues across the profession who've
  50. 2:38been willing to contribute
  51. 2:40lectures to this series and to put a
  52. 2:43stock of knowledge out there that we
  53. 2:45hoped would
  54. 2:46lay a groundwork for doctoral level
  55. 2:48teaching
  56. 2:49on this topic which isn't really offered
  57. 2:51in any one institution
  58. 2:53and so um this lecture fits in perfectly
  59. 2:57the question of how
  60. 2:58urbanization relates to development is
  61. 3:00one that's obviously
  62. 3:01really fundamental to the processes of
  63. 3:04structural change and sectoral
  64. 3:06movements before i turn things over to
  65. 3:09klaus i just want to reiterate some of
  66. 3:10the ground rules which will also be
  67. 3:12familiar
  68. 3:13to all of you those of you in the
  69. 3:15virtual front row will control your own
  70. 3:17cameras and microphones
  71. 3:19klaus says you're more than willing to
  72. 3:21interrupt with questions
  73. 3:23as he goes along please feel free don't
  74. 3:25be shy
  75. 3:26for those of you who are not in the
  76. 3:28front row
  77. 3:29the way for you to ask questions is to
  78. 3:32pose them
  79. 3:32in the q a section so use that feature
  80. 3:37um klaus won't be able to see those
  81. 3:39questions but i and joe kaboski will do
  82. 3:42our best to answer as many of those
  83. 3:43questions as we can
  84. 3:45and the ones that we can't answer that
  85. 3:47are really hard and difficult
  86. 3:48we'll hand over to klaus and make him
  87. 3:50answer um
  88. 3:52and i think that's i think those are the
  89. 3:54key bits of information that we need
  90. 3:57so again without further ado i will turn
  91. 3:59things over to klaus
  92. 4:01and please go ahead and share your
  93. 4:03slides
  94. 4:04um for those watching the slides are all
  95. 4:07online i'll
  96. 4:08i will make sure that the link gets to
  97. 4:10you and
  98. 4:12please feel free to follow along klaus
  99. 4:14over to you
  100. 4:16thank you uh doug for the kind uh
  101. 4:18introduction it's uh
  102. 4:20it's a real pleasure to uh to be here
  103. 4:23today and uh to be able to talk to
  104. 4:26uh all of you about this important topic
  105. 4:29development and urbanization
  106. 4:33so i will divide
  107. 4:37my lecture today
  108. 4:40in two parts most of it
  109. 4:43i will dedicate to the discussion of
  110. 4:47one particular paper which i wrote
  111. 4:51a couple of years ago with a colleague
  112. 4:55with esteban rossi hamsburg
  113. 4:58on determinants
  114. 5:01of the city size distribution
  115. 5:04in particular in that paper we looked at
  116. 5:08the role of three important determinants
  117. 5:12in the city size distribution uh
  118. 5:15productivity or efficiency amenities
  119. 5:19and urban frictions and then we apply
  120. 5:23actually our methodology to look at the
  121. 5:26us and china
  122. 5:27and so you could ask yourself uh
  123. 5:30how is this related to uh
  124. 5:33to development well of course as you all
  125. 5:37know
  126. 5:38uh the development process uh is
  127. 5:41typically accompanied
  128. 5:42by um urbanization by people moving from
  129. 5:47rural areas to uh to cities
  130. 5:51and that leads to a number of challenges
  131. 5:54right so for example there's always this
  132. 5:57big
  133. 5:57question whether some of the world's
  134. 6:01mega cities are becoming
  135. 6:04too big right and this type of approach
  136. 6:07that i will
  137. 6:08be talking about to you today will be
  138. 6:10able to
  139. 6:12uh give you a framework
  140. 6:15uh to think about that question and to
  141. 6:17actually quantitatively
  142. 6:19assess that question so that's one
  143. 6:23reason why
  144. 6:25we think this is important another
  145. 6:27reason is that
  146. 6:29as you all know in many many countries
  147. 6:33uh governments are very worried about
  148. 6:37the spatial distribution
  149. 6:39of economic activity right so maybe
  150. 6:42development is too conscious
  151. 6:44concentrated in particular areas and
  152. 6:47they want to
  153. 6:48spread it over the territory and once
  154. 6:51again you can ask yourself
  155. 6:53is that a reasonable policy or is it not
  156. 6:57you know what are the welfare effects
  157. 6:59for example of
  158. 7:00a policy that would uh
  159. 7:03promote growth in for instance medium
  160. 7:08medium-sized or small-sized cities is
  161. 7:11that something that
  162. 7:12makes sense right so it may make sense
  163. 7:14from a territorial perspective
  164. 7:16does it also make sense from a welfare
  165. 7:18perspective so all these questions one
  166. 7:20one can ask by by applying the
  167. 7:23methodology
  168. 7:25i will be talking about today
  169. 7:28and then lastly maybe as as part of the
  170. 7:30motivation
  171. 7:32is that we think there's a lot of value
  172. 7:36in comparing urban systems
  173. 7:40uh across countries right so as i said
  174. 7:43our
  175. 7:44our initial analysis was done
  176. 7:47uh on the united states it's obviously
  177. 7:50not a developing country
  178. 7:51but you know you can learn a lot from
  179. 7:53say let me take
  180. 7:55this particular approach let me
  181. 7:58do the same exercise in china
  182. 8:01let me do the same exercise in mexico
  183. 8:04let me do the same
  184. 8:06exercise in nigeria and try to
  185. 8:08understand
  186. 8:09what are the similarities what are the
  187. 8:11differences
  188. 8:12what can we learn from one country
  189. 8:16for example might it be the case
  190. 8:19that china is slowly moving
  191. 8:22into in the direction of
  192. 8:26the urban system that we have in the u.s
  193. 8:28and if so
  194. 8:30what does that imply in terms of
  195. 8:33future gains or losses in terms of
  196. 8:38welfare right so there's lots of
  197. 8:40interesting questions here
  198. 8:41and so that's going to be the main part
  199. 8:44of my lecture and then towards the end
  200. 8:47of the lecture i will want to talk a
  201. 8:49little bit about a few
  202. 8:52other papers uh just to give you a
  203. 8:55flavor
  204. 8:56of the other work that has been done and
  205. 8:58that is being done
  206. 9:00in the area of
  207. 9:03urban economics and development or even
  208. 9:06more broadly
  209. 9:08what we could call spatial economics
  210. 9:11and development so the difference a bit
  211. 9:13between urban
  212. 9:15and spatial would be urban is mostly
  213. 9:18focusing
  214. 9:20on uh cities
  215. 9:23as the word itself says versus
  216. 9:26a more spatial economics approach a more
  217. 9:29economic geography approach
  218. 9:31would would be a little more
  219. 9:32comprehensive and take
  220. 9:34take the entire territory or the entire
  221. 9:38geography of a country including uh
  222. 9:40including say uh rural areas
  223. 9:44etc etc okay so without
  224. 9:48without uh holding you up further let me
  225. 9:52now turn to the model i will explain
  226. 9:55this in some detail and then show you
  227. 9:57some graphs and then move on
  228. 9:59okay so um so as i told you in the
  229. 10:02beginning
  230. 10:03we will be looking at three
  231. 10:06determinants of what makes
  232. 10:10a city an attractive place to live
  233. 10:14right so one determinant could simply be
  234. 10:17that
  235. 10:18the location has a high level of
  236. 10:20productivity
  237. 10:21so i can move to a city be highly
  238. 10:24productive
  239. 10:25earn a decent wage and that makes the
  240. 10:27city attractive
  241. 10:29a second reason could be attractive
  242. 10:32amenities
  243. 10:33right so people don't only live in
  244. 10:35cities for productive purposes
  245. 10:38they also live in cities for
  246. 10:43consumption purposes in fact it's
  247. 10:45something that that doug
  248. 10:46has written about and hopefully we will
  249. 10:48get to talking a bit about
  250. 10:50some of his work as well uh and then
  251. 10:53lastly um
  252. 10:56some cities are of course better than
  253. 10:59others
  254. 11:00in terms of managing
  255. 11:03what we call frictions but you can think
  256. 11:05of frictions as
  257. 11:06urban costs right and this is
  258. 11:08particularly important
  259. 11:10in developing countries so we all know
  260. 11:13that
  261. 11:13that cities are great places to be
  262. 11:15productive uh
  263. 11:17that density is a good thing uh it helps
  264. 11:20us
  265. 11:21it helps us be productive but on the
  266. 11:22other on the other hand
  267. 11:24it also leads to urban costs right
  268. 11:27cities
  269. 11:28tend to be congested cities tend to be
  270. 11:30polluted
  271. 11:31et cetera et cetera and some
  272. 11:34cities are better at managing that than
  273. 11:38others
  274. 11:38right um so so so that's those are the
  275. 11:42three determinants we're going to look
  276. 11:43at
  277. 11:44and then the second element of the
  278. 11:46approach is that
  279. 11:47we will not look at a single city
  280. 11:51but instead we will look at the entire
  281. 11:54system of cities what that means is if i
  282. 11:57take
  283. 11:57say the u.s or i take china i'm going to
  284. 12:00take all the cities in the u.s or
  285. 12:02take all the cities in china and what's
  286. 12:04important about that approach
  287. 12:06is that this is a general equilibrium
  288. 12:10approach meaning
  289. 12:11that if um
  290. 12:15one city is attractive
  291. 12:19for example that may be because the city
  292. 12:22itself
  293. 12:23has some good features but it also may
  294. 12:25be because other cities are less
  295. 12:26attractive
  296. 12:27right so it's a system where people uh
  297. 12:30can can move across space and so how
  298. 12:33well i do
  299. 12:35will obviously depend partly on how well
  300. 12:39others do and and i think that approach
  301. 12:41of a system of cities is important
  302. 12:43because very often when we think about
  303. 12:45urban policy
  304. 12:46urban policy is very often run by city
  305. 12:50governments
  306. 12:51right and so a city may say i want to do
  307. 12:53this
  308. 12:54to make my place more attractive but
  309. 12:57that doesn't necessarily mean
  310. 12:59that that is the best thing to do from
  311. 13:02a systemic uh point of view right and so
  312. 13:06taking into account uh the entire system
  313. 13:09of cities i think is
  314. 13:10is a useful is a useful approach and so
  315. 13:13once we have this model and once we can
  316. 13:15quantify
  317. 13:16we'll obviously be able to run some
  318. 13:18counterfactual exercises
  319. 13:20and the counter factual exercises will
  320. 13:22be a little bit
  321. 13:23uh along the lines of what i was um
  322. 13:27talking about in in the introduction i
  323. 13:30can for example look
  324. 13:31at would it make sense uh to uh
  325. 13:35support smaller cities would it make
  326. 13:37sense
  327. 13:38to uh try to slow down
  328. 13:42growth in in bigger cities etc
  329. 13:45right and then as i said we will compare
  330. 13:47the us
  331. 13:48and china okay so the model
  332. 13:52we have a system of i
  333. 13:55cities each city will be characterized
  334. 13:58by a level of productivity
  335. 14:00by a level of amenities and then a level
  336. 14:03of what we call
  337. 14:04excessive frictions which reflect this
  338. 14:06efficiency of providing
  339. 14:08uh urban infrastructure that deals with
  340. 14:11that deals with congestion i'll have to
  341. 14:13be a little bit more specific about
  342. 14:15that third point in a in a second
  343. 14:18okay and then we'll have uh n
  344. 14:21agents or individuals or households and
  345. 14:24they can choose where they live and work
  346. 14:27and so the urban equilibrium will be one
  347. 14:30where
  348. 14:31utility uh equalizes across
  349. 14:35space so in terms of technology
  350. 14:39so we have goods that are being produced
  351. 14:42in these different cities
  352. 14:44as i said uh a city i will have a
  353. 14:46particular productivity
  354. 14:48ait and then production will depend on
  355. 14:52that productivity
  356. 14:53it will depend on capital and it will
  357. 14:55depend
  358. 14:56on on hours worked right
  359. 15:00capital will be freely mobile across pay
  360. 15:02so there will be a
  361. 15:03common a common interest rate in terms
  362. 15:06of
  363. 15:07preferences we will say that preferences
  364. 15:10depend
  365. 15:11on your consumption right it will also
  366. 15:14depend
  367. 15:16on your leisure right so i have one
  368. 15:18minus h
  369. 15:20where h is the hours you work the more
  370. 15:22you work
  371. 15:23the less utility you have so i have
  372. 15:25consumption i have leisure
  373. 15:27and then i have this gamma term in here
  374. 15:30gamma i
  375. 15:31i is a subscript for a particular city
  376. 15:34which will denote
  377. 15:35the city's amenities right and so we'll
  378. 15:38take that as a as a
  379. 15:40fixed characteristic in the exercise
  380. 15:43we're doing
  381. 15:44that just could be that you know if your
  382. 15:46city
  383. 15:47is one of the students i can see you
  384. 15:49have the golden gate bridge behind you
  385. 15:51if your city is located in the san
  386. 15:54francisco bay area
  387. 15:55well that's just a nice location that
  388. 15:58will add to the amenities
  389. 16:00of of that place right so so then
  390. 16:03the agent will obviously maximize
  391. 16:05utility subject to
  392. 16:07it to a budget constraint and without
  393. 16:09going into too much too many details
  394. 16:11here
  395. 16:12i just want to flag one thing in a
  396. 16:14budget constraint here
  397. 16:15or a few things one is that um
  398. 16:19that there will be a tax rate
  399. 16:22tau right which is levied on
  400. 16:26people's wages and that tax rate tau
  401. 16:30is actually what's going to finance
  402. 16:33the urban infrastructure right so people
  403. 16:36are going to be living
  404. 16:37in in this city they will need to be
  405. 16:39able to commute to work
  406. 16:41and the city will have to provide urban
  407. 16:42infrastructure
  408. 16:44call it roads or commuting
  409. 16:45infrastructure and that will cost
  410. 16:47something and that's what we're going to
  411. 16:49be calling it
  412. 16:51that's going to be financed by this tax
  413. 16:53style
  414. 16:55r will be referring to the fact that
  415. 16:58people live on on land and they need to
  416. 17:00pay rent
  417. 17:02and then t will refer to commuting but i
  418. 17:05will get
  419. 17:05i will get to that in in a second um
  420. 17:09okay so you can you can solve this uh
  421. 17:12this
  422. 17:12utility maximization problem and you get
  423. 17:15this first order condition
  424. 17:17right which obviously will depend uh on
  425. 17:20this
  426. 17:21tax tau and so the stack style will
  427. 17:25distort
  428. 17:26obviously your your your optimal
  429. 17:30decision
  430. 17:30of how much you want to how much you
  431. 17:33want to
  432. 17:34work right because it's a tax on labor
  433. 17:38and so sometimes in the literature
  434. 17:40rather than calling this
  435. 17:41tau a tax some people prefer to refer to
  436. 17:45tao
  437. 17:46as a labor wedge uh what's the
  438. 17:49difference between the two
  439. 17:51the the difference between the two is
  440. 17:53tao as a tax is obviously
  441. 17:55a very concrete concept you say okay
  442. 17:58there's a tax rate of say
  443. 18:00seven and a half percent and that's what
  444. 18:02i'm gonna call tao
  445. 18:03versus saying no no no tau is anything
  446. 18:07that kind of distorts my decision of
  447. 18:10how much how many hours i want to work
  448. 18:13and that could partly be
  449. 18:14taxes but it could partly be other
  450. 18:19maybe frictions or regulations or
  451. 18:23things that have to do with the context
  452. 18:26in which i live
  453. 18:27which which distort my decisions and so
  454. 18:30if you take that broader view then we
  455. 18:33would refer to tao as a labor wedge
  456. 18:35right and so what you have to understand
  457. 18:37is that when we call it the labor wage
  458. 18:39it's partly referring to taxes but it
  459. 18:41could partly be referring to other
  460. 18:43things
  461. 18:44and it's a bit of a black black box kind
  462. 18:47of approach
  463. 18:48where where we don't really want to be
  464. 18:51too specific of
  465. 18:52what other things might be in that towel
  466. 18:55right
  467. 18:56and so anyway that's just a bit of a of
  468. 18:59a side note here
  469. 19:00and then as i said agents will be
  470. 19:04freely mobile across cities and so
  471. 19:08utility will equalize across space
  472. 19:11okay uh so uh right
  473. 19:15for now i haven't really said anything
  474. 19:18yet about
  475. 19:19uh what it means to be a city the only
  476. 19:22thing i've said is there's these
  477. 19:23different
  478. 19:24points in space that have different
  479. 19:26productivity levels
  480. 19:27different amenity levels and different
  481. 19:29taxes and then people will allocate
  482. 19:31themselves
  483. 19:32across space until utility equalizes
  484. 19:35across all these points but what exactly
  485. 19:38does it mean
  486. 19:39here to be a city and can we give some
  487. 19:41more structure to what it means to be a
  488. 19:43city
  489. 19:44right and so a very standard model
  490. 19:47that is used in urban economics
  491. 19:50is called the monocentric city model
  492. 19:54and so the monocentric city model uh
  493. 19:57what it tries to
  494. 20:00what it tries to kind of conceptualize
  495. 20:02is the idea
  496. 20:04that uh cities are not only productive
  497. 20:08places but cities also
  498. 20:10cause some kind of congestion because
  499. 20:13people need to live
  500. 20:14somewhere and then they need to get to
  501. 20:16work right and the monocentric model
  502. 20:19the assumptions it makes is that
  503. 20:22production
  504. 20:23happens at the city center right call
  505. 20:26that sort of the central business
  506. 20:27district
  507. 20:28and then people live in concentric
  508. 20:32circles around that city center
  509. 20:36of course at different distances right
  510. 20:38they go away from the center
  511. 20:40we will assume that every individual
  512. 20:44occupies one unit of land and so as
  513. 20:48more people move to the city the city
  514. 20:51will grow
  515. 20:52and the distance from the furthest away
  516. 20:55resident to the city center
  517. 20:56will of course also grow and so then you
  518. 20:59face a trade-off
  519. 21:00right the people who are going to be
  520. 21:02living further away
  521. 21:04will have to commute longer distances
  522. 21:08right commuting is costly you can model
  523. 21:10this in different ways you can think of
  524. 21:12commuting being costly in terms of time
  525. 21:15we we modeled it here in this particular
  526. 21:18paper
  527. 21:19as commuting being costly in terms of
  528. 21:21goods
  529. 21:23and so the commuting cost td
  530. 21:26d being the distance from where you live
  531. 21:28to the city center
  532. 21:29will be kappa d right so some kind of
  533. 21:33a parameter times times the distance
  534. 21:36now as i said people live on on everyone
  535. 21:39lives on one unit of land
  536. 21:40and pays a particular rent rd
  537. 21:44which also changes with distance and we
  538. 21:46will normalize
  539. 21:48the price at the price of land
  540. 21:51at the city border sort of at the fringe
  541. 21:54of the city
  542. 21:55we will set that equal to zero you can
  543. 21:57set it equal to a
  544. 21:58concept it doesn't matter but we'll set
  545. 22:00that equal to zero
  546. 22:01so r d d bar where d bar is the
  547. 22:05the city border let's say right the fir
  548. 22:08the point furthest away from the city
  549. 22:10center
  550. 22:10we'll say that the rents over there are
  551. 22:12equal to zero and then we will
  552. 22:14make the assumption that all agents in a
  553. 22:17city
  554. 22:18can choose where they live if everybody
  555. 22:21can choose where they live
  556. 22:23then the sum of the rents that you pay
  557. 22:27plus the commuting costs that you pay
  558. 22:32that must equalize across people right
  559. 22:34and what that
  560. 22:35implies is that the person living
  561. 22:39furthers away from the city center
  562. 22:41will pay the highest commuting cost
  563. 22:43actually kappa d bar
  564. 22:45but will pay zero rents and then the
  565. 22:47person living closest to the city center
  566. 22:50will actually be paying essentially zero
  567. 22:53commuting costs right
  568. 22:54but will pay the highest rents and so
  569. 22:56you have a
  570. 22:57what they call a rent gradient and
  571. 23:00that's a very typical thing that we see
  572. 23:02in urban economics it's something which
  573. 23:04is very well studied the idea that
  574. 23:06rents tend to decrease
  575. 23:10with distance from the city center
  576. 23:14because it is compensating people
  577. 23:18for for longer commutes anyway and so
  578. 23:21we have the setup and so then you can of
  579. 23:23course if you say everybody lives
  580. 23:26on one unit of land if i have a
  581. 23:28particular population
  582. 23:29nit in the city right
  583. 23:32i can calculate how big the city should
  584. 23:35be i can calculate the radius of the
  585. 23:37city d
  586. 23:37bar once i know how many people live in
  587. 23:41the city and how big the city is
  588. 23:43i can actually also calculate the total
  589. 23:46miles traveled
  590. 23:47right how how what is the total amount
  591. 23:49of commuting
  592. 23:50that is being done in the city and
  593. 23:53what's interesting about that as you can
  594. 23:55see in this
  595. 23:55this expression here is that this is
  596. 23:58actually convex in in
  597. 24:02the number of people who live in the
  598. 24:04city and that gives you a little bit
  599. 24:06this idea that yes
  600. 24:07as cities grow maybe the productivity
  601. 24:10may go up
  602. 24:11but there's also you know congestion
  603. 24:13costs or these costs of of size
  604. 24:16are also increasing in in in in a convex
  605. 24:19way
  606. 24:20and that is actually important for the
  607. 24:22following reason
  608. 24:23if if if congestion wouldn't be um
  609. 24:27increasing in a convex way at the end
  610. 24:32everybody would want to live in the same
  611. 24:34city right which would be say the most
  612. 24:36productive city or the
  613. 24:37the city with the best productivity
  614. 24:39slash the best amenities
  615. 24:41right and so we of course know that in
  616. 24:44reality
  617. 24:45not everybody lives in the same city
  618. 24:47there's many cities across
  619. 24:49the territory and one one important
  620. 24:51reason for that of course is that
  621. 24:54there's a limit to how big a city can be
  622. 24:57right and so if you think of a city
  623. 24:59stretching a hundred miles for example
  624. 25:02but at some point the city becomes too
  625. 25:04big
  626. 25:05and it becomes too costly congestion
  627. 25:08becomes too costly to
  628. 25:09deal with and and so new cities would be
  629. 25:12formed
  630. 25:13okay um so that's kind of the setup
  631. 25:17then uh lastly uh
  632. 25:21so so we have the city we have this need
  633. 25:24to commute
  634. 25:25uh the government city government in
  635. 25:28this case
  636. 25:28will have to provide urban
  637. 25:31infrastructure
  638. 25:32transport infrastructure uh to uh
  639. 25:35to to have these people to have its
  640. 25:37residents
  641. 25:38uh commute and what we will assume is
  642. 25:41that
  643. 25:42the the cost of providing this transport
  644. 25:45infrastructure
  645. 25:46will depend on the total commuting cost
  646. 25:49which is this this expression here that
  647. 25:51you see at the end
  648. 25:52times the kappa and it will also depend
  649. 25:55on
  650. 25:56wages right of a worker
  651. 25:59or workers wage is actually w times h
  652. 26:02but then it will also depend
  653. 26:04on this uh this variable which we call
  654. 26:08git and this is what we will call the
  655. 26:11inefficiency or the frictions or these
  656. 26:13excessive frictions
  657. 26:14of of different city governments and so
  658. 26:17to be
  659. 26:18to be to be very clear what we kind of
  660. 26:21mean by g is the following
  661. 26:25g is not referring to the fact that
  662. 26:28bigger cities
  663. 26:29become more congested it's it's more the
  664. 26:32idea that
  665. 26:33if i take two cities of equal size
  666. 26:37right that are equally congested right
  667. 26:41in terms of how much commuting happens
  668. 26:43etc
  669. 26:44some city governments are better
  670. 26:47are more efficient at
  671. 26:51dealing with this than others they're
  672. 26:53they're more efficient at providing this
  673. 26:55infrastructure than others
  674. 26:56the one that's more efficient would have
  675. 26:59a higher g
  676. 27:00sorry would have a lower a lower g the
  677. 27:02one that's less efficient
  678. 27:04would have a higher g right and so
  679. 27:06that's why we in the paper we refer to
  680. 27:08this as excessive frictions
  681. 27:10because typically yes as cities grow
  682. 27:12frictions increase
  683. 27:14but but given those that increase in
  684. 27:17frictions
  685. 27:18some are bet some some city governments
  686. 27:20are better and some are worse
  687. 27:21at actually providing those those uh
  688. 27:25that infrastructure they're better or
  689. 27:26worse in terms of
  690. 27:28dealing with uh with those frictions
  691. 27:31okay so
  692. 27:32so that's kind of the idea and
  693. 27:36and and of course all these costs of
  694. 27:38providing transport infrastructure is
  695. 27:41then what will be
  696. 27:45financed by that labor
  697. 27:48tax towel okay um
  698. 27:51all right well um then of course
  699. 27:54characterization of equilibrium is
  700. 27:55actually very simple
  701. 27:56as i said you know people just allocate
  702. 27:59themselves across space
  703. 28:00until you tilt the equalizers and so
  704. 28:03what we really only need
  705. 28:04so so just to to sort of simplify a bit
  706. 28:08the only uh the only things i kind of
  707. 28:11need to know
  708. 28:13to solve this model is if i have
  709. 28:15information on
  710. 28:17productivity and on amenities
  711. 28:21right i have information on a i have
  712. 28:24information on gamma
  713. 28:25and i have information on this
  714. 28:28efficiency or these frictions with which
  715. 28:31governments supply infrastructure just
  716. 28:35git
  717. 28:36if i have a triplet if i have this
  718. 28:38triplet
  719. 28:39for all cities i then
  720. 28:43i can actually solve the model right i
  721. 28:45can me when
  722. 28:46by solving the model what i mean is i
  723. 28:49can tell you
  724. 28:50how many people will live in every
  725. 28:52single place
  726. 28:53right which is the main thing we're
  727. 28:55looking at because once i know that
  728. 28:57i can of course start looking at what
  729. 28:59does that mean in terms of
  730. 29:01city size distribution what does that
  731. 29:02mean in terms of
  732. 29:04welfare etc etc okay and of course
  733. 29:08as you can imagine the in in equilibrium
  734. 29:11we will find that more productive cities
  735. 29:13will be larger
  736. 29:15we will find that cities with better
  737. 29:18larger
  738. 29:18amenities are also larger and then we
  739. 29:21will find that cities with these
  740. 29:23higher excessive frictions higher git
  741. 29:26will be smaller right and so what we
  742. 29:30will do now
  743. 29:31is i will show you very briefly how we
  744. 29:34get
  745. 29:34data on these on on this triplet
  746. 29:39for all metropolitan areas in the u.s
  747. 29:42and then i can show you
  748. 29:43what we do in terms of exercise uh
  749. 29:47and then i will show you what we do
  750. 29:50for china and the comparison between
  751. 29:54the two will actually be i hope uh quite
  752. 29:57uh
  753. 29:57quite interesting okay uh
  754. 30:01are there any questions on
  755. 30:05the model part
  756. 30:11i was wondering a bit um how realistic
  757. 30:14it is to have these taxes be um
  758. 30:18being like on a city level
  759. 30:22yeah so so so uh you're actually quite
  760. 30:25right some of the more
  761. 30:27simple urban models would just say look
  762. 30:30let us just consider productivity and
  763. 30:33amenities as a two main characteristics
  764. 30:36that make cities different
  765. 30:39and that's kind of enough to understand
  766. 30:43most of the insights we can get from
  767. 30:46urban economics
  768. 30:48here as i said and and that's why
  769. 30:52you know that that's why your your
  770. 30:55question
  771. 30:56is useful um
  772. 30:59you can think of it as being a tax
  773. 31:02and then you can of course ask yourself
  774. 31:04yes well how how might how which part of
  775. 31:06these taxes are actually
  776. 31:07local taxes which part are state taxed
  777. 31:10which part of federal taxes
  778. 31:11it's obvious that part of the urban
  779. 31:14infrastructure
  780. 31:15will actually be let's say city roads
  781. 31:18right
  782. 31:18they typically are financed by
  783. 31:21property taxes which are local taxes
  784. 31:24right and so from that point of view we
  785. 31:26think
  786. 31:27our assumption is actually quite
  787. 31:29reasonable a lot of the
  788. 31:31local commuting infrastructure is
  789. 31:34actually financed
  790. 31:35by by local taxes uh
  791. 31:38but but again it's a bit of a broader
  792. 31:40concept
  793. 31:42uh you can go beyond the idea of
  794. 31:45of of strictly thinking of of it as
  795. 31:47being a tax
  796. 31:48and go to this idea of a labor wedge
  797. 31:52which would which would simply be
  798. 31:54telling you that
  799. 31:56some cities seem to be more efficient
  800. 31:59in terms of dealing with say
  801. 32:02congestion or dealing with urban
  802. 32:04infrastructure than others
  803. 32:06right um yeah so so those are the two
  804. 32:10parts of the
  805. 32:10of the answer but when we when we sort
  806. 32:13of
  807. 32:14get estimates of the style and when i i
  808. 32:18actually correlated those estimates of
  809. 32:20tao that are sort of predicted by the
  810. 32:21model
  811. 32:22and and i compared it to uh local taxes
  812. 32:26the correlation is actually quite high
  813. 32:28so so
  814. 32:29so it correlates well our notion of tau
  815. 32:33in the model actually correlates quite
  816. 32:35well with
  817. 32:37with the local taxes so that's that's
  818. 32:40what i can say about that for now
  819. 32:42um anything else any other quick
  820. 32:45question
  821. 32:45klaus i have a clarifying question for
  822. 32:47you in the
  823. 32:49q a from veronica goyal linking this
  824. 32:51back to the misallocation lectures that
  825. 32:53people have had
  826. 32:54yes if people relocate to a city because
  827. 32:57of
  828. 32:57amenities not productivity
  829. 33:00can that lead to misallocation in the
  830. 33:03aggregate
  831. 33:04how do you think about what's uh what's
  832. 33:06interesting of course is that
  833. 33:10when you have only one characteristic so
  834. 33:12suppose we say the only thing we have
  835. 33:15here
  836. 33:15is productivity then then
  837. 33:19then all these predictions are
  838. 33:20relatively straightforward right you
  839. 33:22want people to go to places
  840. 33:24that are more productive and leave
  841. 33:26places that are less productive and
  842. 33:27you're done
  843. 33:28over here it's a bit more complicated
  844. 33:31because
  845. 33:33not only do we have three determinants
  846. 33:36but
  847. 33:36the question is what are the
  848. 33:38correlations between them
  849. 33:40right is it typically the case that
  850. 33:42higher productive cities
  851. 33:43are also higher amenity cities that may
  852. 33:46be the case yes or maybe no
  853. 33:48and so uh
  854. 33:53so so so what what we can say is that
  855. 33:56if people move to cities with higher
  856. 33:59amenities
  857. 34:00that will of course be that that will
  858. 34:03improve
  859. 34:03their utility right and so it will
  860. 34:07improve welfare but but it may actually
  861. 34:10decrease
  862. 34:10uh it may decrease efficiency if it
  863. 34:14turns out that the higher amenity
  864. 34:16cities are cities with lower with lower
  865. 34:19efficiency
  866. 34:20right and so if you take if you take a
  867. 34:23view of
  868. 34:24misallocation as only referring to
  869. 34:27misallocation from the efficiency point
  870. 34:29of view
  871. 34:30versus if you take a view of
  872. 34:32misallocation
  873. 34:34from a welfare point of view right and
  874. 34:35so we're talking here about
  875. 34:37welfare and so yes it is possible that
  876. 34:41as you are maximizing welfare by letting
  877. 34:44people move
  878. 34:45where they want and they might be going
  879. 34:47to places with better amenities
  880. 34:49that that efficiency actually goes down
  881. 34:52that's possible
  882. 34:55okay sorry i also have a question about
  883. 34:58the
  884. 34:59labor tax yes
  885. 35:02i'm not sure whether i understand it
  886. 35:04right but uh
  887. 35:06in the production function it seems that
  888. 35:08the
  889. 35:09liberal text doesn't distort the
  890. 35:12production i think so the which is what
  891. 35:15it does is it it
  892. 35:16it affects uh if you go back here it
  893. 35:19affects
  894. 35:20the choice of the hours worked
  895. 35:24right and so you can kind of see this
  896. 35:26here from
  897. 35:27the tao entering into your into your
  898. 35:30budget constraints so so the tau will
  899. 35:33depend on the hours you work so it's not
  900. 35:35it's not a sort of it's not a tax that's
  901. 35:38fixed
  902. 35:38per person it's a tax that depends on
  903. 35:41how many hours you work
  904. 35:43and so when you think about the
  905. 35:45equalizing marginal
  906. 35:48marginal benefit and marginal cost
  907. 35:51higher labor taxes will
  908. 35:54push you towards working uh less
  909. 35:58hours which is something you can see in
  910. 36:00this first sort of condition here
  911. 36:02right and so so in that sense it is a
  912. 36:05it's a sort of a standard distortionary
  913. 36:09labor tax okay
  914. 36:14okay one more question um
  915. 36:18how about the
  916. 36:21the the key assumption is that the the
  917. 36:23cities are homogeneous right
  918. 36:29in what sense i mean are we looking at
  919. 36:31the structure
  920. 36:33and the factors that uh
  921. 36:36determine uh these
  922. 36:39cities are common to all is that is that
  923. 36:42is it clear to say yeah so so well so so
  924. 36:46uh so of course each city
  925. 36:49has a different so here as you can see
  926. 36:51this ait the gamma i t and the git are
  927. 36:54really the
  928. 36:55the three fundamental drivers and so the
  929. 36:58only thing is that the i
  930. 37:00so so the structure is the same yeah so
  931. 37:02the the model is of course the same
  932. 37:04model and what makes one city
  933. 37:06attractive or another it's the same
  934. 37:08types of determinants
  935. 37:09but but they do have an eye subscript
  936. 37:12meaning
  937. 37:13these are three characteristics which
  938. 37:16are
  939. 37:16city specific so different cities will
  940. 37:18obviously have different levels of these
  941. 37:20three
  942. 37:21of these three determinants but
  943. 37:23otherwise yes the structure
  944. 37:25the structure is the same for all the
  945. 37:27cities okay how do we account for
  946. 37:30endowment and maybe some cities are
  947. 37:33endowed with certain
  948. 37:34uh maybe resources um yeah so so that
  949. 37:38would actually in
  950. 37:39that would show up in our in a higher
  951. 37:42ait
  952. 37:43okay right so a city that is for example
  953. 37:46either well endowed with some natural
  954. 37:48resources or maybe
  955. 37:50uh located in a port in in a place
  956. 37:53that's
  957. 37:54that's easily accessible that that that
  958. 37:57would that would show up in the ait
  959. 37:59okay thank you okay all right
  960. 38:02and so then what do we do we have data
  961. 38:04on all these metropolitan areas in the
  962. 38:06u.s
  963. 38:07uh production we measure by gdp
  964. 38:11consumption we don't really have data on
  965. 38:14consumption by
  966. 38:16by msa by metropolitan area and so we
  967. 38:19actually use uh
  968. 38:20retail earnings and then adjust for
  969. 38:23national averages
  970. 38:25to get to get
  971. 38:28a measure of consumption at the city
  972. 38:30level and we add to that
  973. 38:33housing housing consumption
  974. 38:36capital we take actually u.s sector
  975. 38:39capital stocks
  976. 38:40and allocated to msas according to
  977. 38:44their shares and in sector learnings and
  978. 38:46then for hours work we use
  979. 38:48the current population survey um so how
  980. 38:51do we get ait
  981. 38:53ait we just get from this expression
  982. 38:56here so we have a measure for y
  983. 38:58for k and for h so we get ait that way
  984. 39:02the labor wedge of course we need some
  985. 39:05assumptions on what
  986. 39:06size and theta etc but we have a measure
  987. 39:09of
  988. 39:10of c of h and of a so we can back out
  989. 39:14tau then the excessive frictions git we
  990. 39:18actually take the govern
  991. 39:19government budget constraint uh we take
  992. 39:22logs
  993. 39:23and then we run this regression here and
  994. 39:26the residual is actually
  995. 39:28what we call uh uh is the log of git so
  996. 39:31we can back out git this way
  997. 39:33and then the manatee levels we it is
  998. 39:36kind of a residual
  999. 39:38right so we we use the model
  1000. 39:42and then
  1001. 39:45determine the amenity levels gamma i t
  1002. 39:50so that the model generated
  1003. 39:53distribution of people across cities
  1004. 39:55actually matches
  1005. 39:57the one that we see in the data
  1006. 40:00okay all right so let me
  1007. 40:04and then we also have a way of getting
  1008. 40:07getting an estimate of kappa right kappa
  1009. 40:10is if you remember that's the cost of
  1010. 40:13the cost of commuting per per mile or
  1011. 40:16per kilometer
  1012. 40:18traveled okay so so with all of this
  1013. 40:21we can you know once we have the as i
  1014. 40:22said once you have these triplets for
  1015. 40:24all the msas
  1016. 40:26and you have parameter values you can
  1017. 40:28just uh
  1018. 40:29allocate people across cities and and
  1019. 40:31then you can start doing some exercises
  1020. 40:33okay that's that's the nature of what
  1021. 40:36we're doing here uh
  1022. 40:38here's one graph just sort of
  1023. 40:40introductory
  1024. 40:41uh to because you'll see a lot of these
  1025. 40:43types of graphs
  1026. 40:44so these types of graphs you may have
  1027. 40:47seen in other
  1028. 40:48lectures or in in your career in
  1029. 40:51economics
  1030. 40:52this type of graph to represent size
  1031. 40:55distributions
  1032. 40:56you know farm size distribution or
  1033. 40:58whatever here it's the
  1034. 41:00city size distribution and so what we
  1035. 41:02have on the
  1036. 41:04x-axis the horizontal axis is the
  1037. 41:08log of population and what i have on my
  1038. 41:10y-axis
  1039. 41:12is the log of the probability
  1040. 41:16of being bigger than the population on
  1041. 41:18the on the on the x-axis
  1042. 41:20so that's a little bit of a of a
  1043. 41:22mouthful
  1044. 41:23uh but but the way to maybe easier for
  1045. 41:26me to say is
  1046. 41:27the way to interpret these these graphs
  1047. 41:30are
  1048. 41:30if the graphs are flatter right
  1049. 41:34say the red one or the orange one
  1050. 41:36[Music]
  1051. 41:37then you have more dispersion
  1052. 41:40in the city size distribution you know
  1053. 41:43on the top
  1054. 41:44the top kind of the smaller cities right
  1055. 41:46so i have more small
  1056. 41:47cities and i have more large cities
  1057. 41:51right so it's a little more dispersed if
  1058. 41:54if it's a little steeper right then
  1059. 41:57there's less dispersion meaning
  1060. 42:01uh the city sizes are of more
  1061. 42:04equal equal size and so
  1062. 42:10excuse me just as a as an example here
  1063. 42:13for instance if you compare
  1064. 42:16the red the red
  1065. 42:21the red curve to the blue one
  1066. 42:25the red one is for a lower level of
  1067. 42:28commuting cost
  1068. 42:29than the blue one so think about what
  1069. 42:31that means
  1070. 42:32intuitively if if i increase commuting
  1071. 42:36costs
  1072. 42:37who is that going to be bad for well
  1073. 42:39that's typically going to be bad
  1074. 42:41for cities where there's a lot of
  1075. 42:42commuting right so that will be
  1076. 42:45bad let's say for the bigger cities
  1077. 42:47right and so
  1078. 42:48higher kappa would tend to make
  1079. 42:52the bigger cities smaller and the
  1080. 42:54smaller cities bigger
  1081. 42:56right that explains why the blue or the
  1082. 42:59light blue curve
  1083. 43:00is kind of steeper than
  1084. 43:04the red one so the red one is for lower
  1085. 43:07commuting costs
  1086. 43:09it's not as costly to be big so i see a
  1087. 43:11more dispersed city sizes
  1088. 43:13distribution for higher commuting cost
  1089. 43:16i see a less dispersed city size
  1090. 43:20distribution
  1091. 43:21okay and of course then you can look at
  1092. 43:25utility and welfare etc but let me move
  1093. 43:27on
  1094. 43:28in the in the interest of time here so
  1095. 43:30so here's the first
  1096. 43:32exercise where what we do
  1097. 43:35is the following we say
  1098. 43:39what would happen to the city size
  1099. 43:43distribution
  1100. 43:45if for example we eliminated
  1101. 43:50all productivity differences across
  1102. 43:52space
  1103. 43:53right or what would happen to the city
  1104. 43:56size distribution
  1105. 43:58if we eliminated all amenity differences
  1106. 44:01across space
  1107. 44:03and so just just to explain a little bit
  1108. 44:05better
  1109. 44:06the blue curve in all four pictures
  1110. 44:10is the actual city size distribution
  1111. 44:13right the ones that are colored in
  1112. 44:16in another color not blue are counter
  1113. 44:19factual city size distributions
  1114. 44:21so let me for example uh
  1115. 44:24call your attention to the one on the
  1116. 44:26top right
  1117. 44:28so the green curve is
  1118. 44:31the city size distribution that i would
  1119. 44:34get
  1120. 44:35if all cities had the same
  1121. 44:39efficiency level in the u.s right
  1122. 44:42the purple one here at the bottom left
  1123. 44:45is
  1124. 44:45what would the city size distribution
  1125. 44:47look like if all cities had the same
  1126. 44:49amenity levels and and the black one is
  1127. 44:53what would the city size distribution
  1128. 44:54look like if all
  1129. 44:56cities had the same level
  1130. 44:59of of excessive friction so what you see
  1131. 45:03is a couple of things for example if you
  1132. 45:05look at efficiency
  1133. 45:07yeah you know the city sizes region
  1134. 45:08doesn't look that different
  1135. 45:10there's a little bit uh
  1136. 45:14you know there's maybe a little bit this
  1137. 45:16is some more smaller cities
  1138. 45:19but on the top part of the distribution
  1139. 45:21you don't really see a very big
  1140. 45:22difference
  1141. 45:23in terms of utility equalizing
  1142. 45:27efficiency of cross space
  1143. 45:29now you know the utility goes from 10 to
  1144. 45:3210.12 so
  1145. 45:33there's a little bit of a improvement in
  1146. 45:36utility but again it's not a whole lot
  1147. 45:38right so the the welfare effects is
  1148. 45:42a kind of an increase by 1.2 percent so
  1149. 45:44the welfare effects of equalizing
  1150. 45:47efficiency across space in america is
  1151. 45:49actually not that big
  1152. 45:51although you do get a lot of
  1153. 45:53reallocation
  1154. 45:54so the reallocation here is measured by
  1155. 45:58uh the the increase in the population
  1156. 46:01and the cities that are growing
  1157. 46:03divided by the total population so you
  1158. 46:06do get a lot of reallocation
  1159. 46:08a lot of people moving across space but
  1160. 46:10the city size distribution is not
  1161. 46:12changing very much
  1162. 46:13and overall utility is not changing very
  1163. 46:16much either
  1164. 46:17and so you look at these utility numbers
  1165. 46:19here and that's true for efficiency
  1166. 46:22it's true for equalizing amenities
  1167. 46:25across space it's true for equalizing uh
  1168. 46:29[Music]
  1169. 46:30excessive frictions across space but but
  1170. 46:32in all three cases the reallocation is
  1171. 46:35relatively big
  1172. 46:36welfare effects are relatively small
  1173. 46:38city size distribution doesn't change
  1174. 46:40very much maybe except in this
  1175. 46:42particular case
  1176. 46:43where you get a much less dispersed
  1177. 46:47city size distribution so that's an
  1178. 46:49interesting
  1179. 46:50first observation right
  1180. 46:53you can of course do many things with
  1181. 46:56this
  1182. 46:58rather than looking at the the the
  1183. 47:01entire distribution
  1184. 47:02you could say let me look at
  1185. 47:05certain particular cities what happens
  1186. 47:08to them
  1187. 47:09right so for instance let me look at
  1188. 47:12efficiency here
  1189. 47:13if you equalize efficiency across space
  1190. 47:17look at the city size distribution you
  1191. 47:19don't see that much happening
  1192. 47:20but but when you look at the data for
  1193. 47:22individual cities
  1194. 47:24the effects are actually quite big yeah
  1195. 47:26well not surprising the most efficient
  1196. 47:28cities will obviously lose
  1197. 47:30that's what happens when you equalize
  1198. 47:32efficiency across space of course others
  1199. 47:34that are less efficient will gain
  1200. 47:36right and so uh at the individual city
  1201. 47:39level
  1202. 47:40you see big changes that's of course
  1203. 47:42what then explains
  1204. 47:44the big reallocation across space you
  1205. 47:47know there wouldn't be bigger
  1206. 47:48reallocation across space
  1207. 47:50if if there's no big effects at the
  1208. 47:53local level
  1209. 47:54right uh the same is true with amenities
  1210. 47:57so if you equalize amenities across
  1211. 47:59space
  1212. 48:00the east coast what gained
  1213. 48:03what does that mean well that means that
  1214. 48:05these places don't have very good
  1215. 48:06amenities
  1216. 48:07right because if they get the average
  1217. 48:09amenity they'll do better
  1218. 48:11the west coast loses but that would
  1219. 48:14tell you that they actually have good
  1220. 48:15amenities if you give them the
  1221. 48:17average amenities they will end up doing
  1222. 48:19worse
  1223. 48:22right so so there's lots of interesting
  1224. 48:24if you're interested in particular
  1225. 48:26cities
  1226. 48:26there's lots of interesting insights uh
  1227. 48:30and there's lots as i said lots of
  1228. 48:31reallocation but not a whole lot of
  1229. 48:34welfare gains and you can look at this
  1230. 48:37in maps
  1231. 48:38for example one interesting thing is
  1232. 48:40that if you eliminate
  1233. 48:42or if you make all these frictions equal
  1234. 48:45across
  1235. 48:46cities the places that are gonna gain
  1236. 48:49are the brown
  1237. 48:50the brown areas so you see a lot of the
  1238. 48:52cities actually in the rust belt
  1239. 48:54uh would be gaining a population
  1240. 48:58if they had the same level of frictions
  1241. 49:00of the rest of the country i thought
  1242. 49:02that was kind of an interesting
  1243. 49:04and interesting finding so lots of lots
  1244. 49:07of
  1245. 49:07cool stuff you can do with this um
  1246. 49:11but let me let me know for the for the
  1247. 49:15remaining 10 minutes before i sort of
  1248. 49:17switch to the second part of the lecture
  1249. 49:19let me actually uh talk a bit about
  1250. 49:23uh china okay um
  1251. 49:26so so we've seen this exercise for the
  1252. 49:29u.s
  1253. 49:30let's do the same exercise for china
  1254. 49:32right
  1255. 49:34well a couple of interesting
  1256. 49:37differences let me focus on the one of
  1257. 49:41productivity then i'll talk a bit about
  1258. 49:43amenities as well but
  1259. 49:44let's look at the top right graph over
  1260. 49:48here
  1261. 49:48so once again the blue curve
  1262. 49:52is the actual observed
  1263. 49:55city size distribution the green one
  1264. 49:58here
  1265. 49:59is how would the city size distribution
  1266. 50:02look like
  1267. 50:03in china if everyone had the same
  1268. 50:07level of productivity okay so the first
  1269. 50:11thing you notice
  1270. 50:12is that
  1271. 50:15uh as you can see this curve has become
  1272. 50:17flatter right
  1273. 50:18flatter remember means more dispersion
  1274. 50:21the bigger cities are actually becoming
  1275. 50:23bigger the smaller cities are becoming
  1276. 50:25smaller
  1277. 50:26right that's interesting uh
  1278. 50:30because you know we've talked a bit
  1279. 50:31about uh mega cities
  1280. 50:34are mega cities desirable are they not
  1281. 50:36desirable etc
  1282. 50:38here we're kind of finding hey you know
  1283. 50:40if everybody had the same efficiency
  1284. 50:41level
  1285. 50:42uh we would see even bigger cities than
  1286. 50:45the ones we see today
  1287. 50:47in china and the cities are as you know
  1288. 50:48already very big in china
  1289. 50:50right and so if anything we'll see
  1290. 50:54more big cities and bigger big cities in
  1291. 50:56china
  1292. 50:57if there is a efficiency efficiency
  1293. 51:00equalizes across space
  1294. 51:01the other very interesting thing here is
  1295. 51:04remember in the case of the us
  1296. 51:06we had a welfare increase of 1.2 percent
  1297. 51:12uh when you equalize efficiency across
  1298. 51:14base here you have a wealthier increase
  1299. 51:16of 46 percent right or 47 percent
  1300. 51:21uh log point but let's let's just call
  1301. 51:24it 47 percent here
  1302. 51:26huge difference huge welfare gains
  1303. 51:29from equalizing efficiency across space
  1304. 51:31so so that of course
  1305. 51:32ties in i think probably with
  1306. 51:36some of the discussions you've had on
  1307. 51:38misallocation
  1308. 51:40in your in your other lectures and so
  1309. 51:43what is very interesting to me about
  1310. 51:45this is
  1311. 51:47you know at some level it shouldn't
  1312. 51:49maybe surprise you
  1313. 51:51right and the reason why maybe this
  1314. 51:52shouldn't surprise you
  1315. 51:54is well as with many other
  1316. 51:58emerging economies
  1317. 52:01you know the difference in efficiency or
  1318. 52:04in productivity across space
  1319. 52:06in china is way way way way bigger
  1320. 52:09than the difference in efficiency across
  1321. 52:12space in the us
  1322. 52:14right in mature economies yes of course
  1323. 52:16there's more efficient
  1324. 52:17places and less efficient places in the
  1325. 52:19u.s but
  1326. 52:20the differences are not that big in
  1327. 52:22china these differences are an order of
  1328. 52:24magnitude bigger they're
  1329. 52:26large right you take the you take the
  1330. 52:28most advanced
  1331. 52:30cities on on the eastern seaboard in
  1332. 52:34china
  1333. 52:34well these cities are very similar to
  1334. 52:38cities in very advanced economies you go
  1335. 52:40all the way
  1336. 52:41to western china and you will find
  1337. 52:44cities that are still very far behind in
  1338. 52:47terms of in terms of development
  1339. 52:49and so that's interesting to observe and
  1340. 52:52so in that sense yes obviously there's a
  1341. 52:54lot of misallocation
  1342. 52:55it's not real misallocation because the
  1343. 52:57efficiency is whatever it is
  1344. 52:59but but there's misallocation in the
  1345. 53:01sense that you know
  1346. 53:02the efficiency hasn't spread to all
  1347. 53:04these places yet if it would
  1348. 53:07then then you would see these big you
  1349. 53:09would see this big
  1350. 53:11you would see this big welfare welfare
  1351. 53:15gains
  1352. 53:16the other thing that's interesting about
  1353. 53:17this counterfactual exercise
  1354. 53:19is that of course if you say let me uh
  1355. 53:23sort of fast forward a couple of decades
  1356. 53:26right maybe 20 30 40 years
  1357. 53:29we kind of know where china is heading
  1358. 53:32obviously
  1359. 53:33because of technology diffusion across
  1360. 53:36space
  1361. 53:37it's very clear that these very
  1362. 53:40large efficiency differences across
  1363. 53:43cities in china
  1364. 53:44will become smaller right that's the
  1365. 53:46standard thing that happens
  1366. 53:49with space and development development
  1367. 53:52typically in the early stages is very
  1368. 53:54uneven across
  1369. 53:55space but then eventually the efficiency
  1370. 53:58diffuses across space
  1371. 54:00making efficiency more equal right and
  1372. 54:03so
  1373. 54:04we we if we had i mean of course we
  1374. 54:07don't know but if you had to make a
  1375. 54:08prediction
  1376. 54:09it's very likely that the spatial
  1377. 54:11differences in efficiency will become
  1378. 54:13smaller
  1379. 54:13and if that's true then it's very likely
  1380. 54:17that we'll see something like this
  1381. 54:18happening in china
  1382. 54:20and that the potential welfare gains
  1383. 54:23from that
  1384. 54:24are actually pretty large and what's
  1385. 54:26interesting about this exercise is that
  1386. 54:28when we say we're making efficiency
  1387. 54:30equal across space
  1388. 54:31it's not that we're giving everybody the
  1389. 54:34best efficiency in the country
  1390. 54:35we're just equalizing it to the average
  1391. 54:38right so we're not
  1392. 54:39increasing we're not increasing
  1393. 54:42average efficiency right the population
  1394. 54:44weighted efficiency is the same
  1395. 54:47as as as as the one in the data
  1396. 54:50right we're just allowing it to be more
  1397. 54:53equally spread across across
  1398. 54:57the geography right and so we we thought
  1399. 55:00that was very interesting because it
  1400. 55:01it's really very very different from
  1401. 55:04what we saw
  1402. 55:06in in the case of the us and again big
  1403. 55:08reallocation et cetera et cetera
  1404. 55:11okay so uh
  1405. 55:14a few more things uh before
  1406. 55:17i finish with this uh part
  1407. 55:21of of the lecture um
  1408. 55:25is is the following i just want to give
  1409. 55:27you a flavor of
  1410. 55:28what other types of exercises could you
  1411. 55:31do
  1412. 55:32with with this uh with this framework
  1413. 55:35so uh one thing we did is
  1414. 55:39we looked at uh
  1415. 55:42a policy or we compared a
  1416. 55:46policy that would target uh
  1417. 55:50lagging cities meaning cities that are
  1418. 55:53behind
  1419. 55:53in terms of either efficiency amenities
  1420. 55:55or frictions
  1421. 55:56versus a policy that would target
  1422. 56:00either medium-sized or small cities
  1423. 56:04and and try to look at what would give
  1424. 56:07us
  1425. 56:08uh the greater or the bigger welfare
  1426. 56:11effects
  1427. 56:11and the reason why we wanted to look at
  1428. 56:13that is because
  1429. 56:16china for a while at least
  1430. 56:19had this policy which i mentioned here
  1431. 56:21at the top in in
  1432. 56:22italics of controlling the big cities
  1433. 56:26moderating the development of
  1434. 56:28medium-sized cities
  1435. 56:29and encouraging the growth of small
  1436. 56:31cities so you can say okay
  1437. 56:32what would happen if we actually gave
  1438. 56:35incentives for small cities to grow
  1439. 56:38would that be a good thing
  1440. 56:40so so here's what you see for instance
  1441. 56:42if you look at
  1442. 56:44the first row of the table this would be
  1443. 56:48what happens if i take the worst cities
  1444. 56:52in terms of either efficiency amenities
  1445. 56:54or frictions and i improve
  1446. 56:56let's say their efficiency by 20
  1447. 56:59okay or i improve their amenities by 20
  1448. 57:03what are the welfare effects in the
  1449. 57:05aggregate
  1450. 57:07right to get a 5 welfare increase you're
  1451. 57:09getting 11 welfare increase
  1452. 57:11in amenities versus if you target the
  1453. 57:14same type of policy
  1454. 57:16but you look at the smallest cities so
  1455. 57:18you you
  1456. 57:19increase the smallest city improve small
  1457. 57:21cities by 20
  1458. 57:23you typically get smaller effects
  1459. 57:27so anyway what this means is you could
  1460. 57:30use
  1461. 57:31a framework like this to uh to look at
  1462. 57:34different policies
  1463. 57:36right it doesn't make sense to target
  1464. 57:38the smaller cities
  1465. 57:39right or or or again does it make sense
  1466. 57:43to try to slow down
  1467. 57:45growth in big cities is that is that a
  1468. 57:47reasonable policy
  1469. 57:48from from the welfare point of view um
  1470. 57:51[Music]
  1471. 57:53so so that's that's kind of the
  1472. 57:55framework here we actually in
  1473. 57:57in a in in another paper also compared
  1474. 58:01uh this exercise or we implemented this
  1475. 58:04exercise for
  1476. 58:06from mexico and in mexico
  1477. 58:09you find something which is somehow
  1478. 58:11somewhere in between
  1479. 58:12china and the us but actually much more
  1480. 58:15close
  1481. 58:16to the us than to china right so we
  1482. 58:18don't find
  1483. 58:19a particularly high welfare effects in
  1484. 58:22mexico either they're a little bit
  1485. 58:23bigger than in the us and so
  1486. 58:25yes it's somewhat in between but but
  1487. 58:28it's much closer to the us than
  1488. 58:30than to china but anyway the good news
  1489. 58:33is
  1490. 58:34if you're interested in this type of
  1491. 58:35approach the data requirements
  1492. 58:39to do these types of exercises are
  1493. 58:43relatively mild you don't need a whole
  1494. 58:46lot of data
  1495. 58:48and as i said i think there's a lot to
  1496. 58:50learn
  1497. 58:51from uh doing this type of analysis
  1498. 58:55in different countries right we learned
  1499. 58:58so much
  1500. 59:00by doing this for china right
  1501. 59:03for in some sense i feel that this paper
  1502. 59:07became really interesting when we did
  1503. 59:09the china exercise
  1504. 59:10right just because the comparison uh
  1505. 59:13taught us so many interesting things
  1506. 59:15and again china is obviously just one
  1507. 59:17country it's an important country
  1508. 59:19and it's an interesting country but
  1509. 59:20there's other countries out there
  1510. 59:22you know there's an urbanization is
  1511. 59:24happening everywhere
  1512. 59:26and it's not happening in the same way
  1513. 59:28everywhere right and so
  1514. 59:30you know maybe it is interesting to do
  1515. 59:32some of these exercises in
  1516. 59:34in some african countries that are going
  1517. 59:36through a process of
  1518. 59:38of of urbanization or you can do this
  1519. 59:41for other
  1520. 59:42south asian or south american countries
  1521. 59:45again there's a lot to learn from doing
  1522. 59:48this
  1523. 59:49for for countries that are going through
  1524. 59:51a process of urbanization
  1525. 59:53in some sense there's probably more to
  1526. 59:56learn from those countries than
  1527. 59:57from doing this exercise for france
  1528. 1:00:01or for italy where things are fairly
  1529. 1:00:04stable and so you can probably guess
  1530. 1:00:06more or less what you will find
  1531. 1:00:09okay the other
  1532. 1:00:12is there any quick question before i
  1533. 1:00:14move on
  1534. 1:00:15and talk very briefly about a few other
  1535. 1:00:17papers
  1536. 1:00:23okay uh i i was
  1537. 1:00:26thinking about uh either way we can
  1538. 1:00:29introduce like
  1539. 1:00:30uh friction related to uh human capital
  1540. 1:00:34institutions like only people with
  1541. 1:00:37some minimum level of an educational
  1542. 1:00:40admin
  1543. 1:00:42are allowed to be in a place as opposed
  1544. 1:00:44to
  1545. 1:00:45people who are lord uh
  1546. 1:00:48other do they create more productive
  1547. 1:00:52cities or yeah so
  1548. 1:00:56so i so you're asking about whether
  1549. 1:00:59there's any role in these models for
  1550. 1:01:01human capital right yeah um
  1551. 1:01:04yes there is i mean we we obviously in
  1552. 1:01:07the paper that i have presented
  1553. 1:01:09i haven't said anything about human
  1554. 1:01:11capital but there is a large
  1555. 1:01:14and growing literature in in urban
  1556. 1:01:17economics
  1557. 1:01:18that has been looking at what they call
  1558. 1:01:22sorting right and it's typically sorting
  1559. 1:01:25of people with different skills to
  1560. 1:01:28different types of cities
  1561. 1:01:30right so you're absolutely right that
  1562. 1:01:32cities are
  1563. 1:01:33different not just because of some kind
  1564. 1:01:35of exogenous level of productivity
  1565. 1:01:38they're also different because they
  1566. 1:01:39attract different type of people
  1567. 1:01:42and there's growing interest in that so
  1568. 1:01:44for a while if you go back say 50
  1569. 1:01:4660 yards the typical urban
  1570. 1:01:50the the urban models that were looking
  1571. 1:01:52at city specialization
  1572. 1:01:54uh they were they would typically look
  1573. 1:01:58at
  1574. 1:01:58sexual specialization they would say oh
  1575. 1:02:00that city
  1576. 1:02:01produces cars and the other city
  1577. 1:02:03produces furniture and the third city
  1578. 1:02:05produces something else
  1579. 1:02:07now there's much more interest
  1580. 1:02:10in not really what they call sexual
  1581. 1:02:12specialization but
  1582. 1:02:14a functional specialization and sorting
  1583. 1:02:17of
  1584. 1:02:18people of different skills to different
  1585. 1:02:21cities
  1586. 1:02:22right so what makes a city an attractive
  1587. 1:02:26place
  1588. 1:02:27for someone who's highly educated right
  1589. 1:02:31and it's a very important question and
  1590. 1:02:32city governments are obviously super
  1591. 1:02:34interested in that because they all want
  1592. 1:02:36to track those types of people
  1593. 1:02:38maybe they are looking for urban
  1594. 1:02:39amenities right maybe
  1595. 1:02:41they're looking for like-minded people
  1596. 1:02:44and because of that you get these you
  1597. 1:02:47get these phenomena
  1598. 1:02:48of sorting right so people people want
  1599. 1:02:50to live in a place
  1600. 1:02:52partly the sorting happens because of
  1601. 1:02:54productive reasons but partly the
  1602. 1:02:55sorting also happens because of
  1603. 1:02:57uh utility and consumption reasons right
  1604. 1:03:00there's
  1605. 1:03:01people may just want to live in a
  1606. 1:03:02particular area or particular city or
  1607. 1:03:04particular neighborhood
  1608. 1:03:06because they find like-minded people
  1609. 1:03:08right and so
  1610. 1:03:09uh being attractive for human capital is
  1611. 1:03:12is interesting again in this particular
  1612. 1:03:15paper
  1613. 1:03:16we we didn't consider a heterogeneity
  1614. 1:03:18and skill
  1615. 1:03:19but that's something that could be
  1616. 1:03:21introduced and as i said there's
  1617. 1:03:22there's lots of interest in urban
  1618. 1:03:24economics in those in those types of
  1619. 1:03:26questions
  1620. 1:03:28thank you yeah thank you a really quick
  1621. 1:03:31one for you
  1622. 1:03:32um in in these models does zipf's law
  1623. 1:03:35hold
  1624. 1:03:35for city size distribution um
  1625. 1:03:39that's a that's uh that's an interesting
  1626. 1:03:41question so
  1627. 1:03:42so yes it i mean the zips law holds
  1628. 1:03:46as you know for for typically for for
  1629. 1:03:49pretty much
  1630. 1:03:49all the city sizes and size distribution
  1631. 1:03:52so
  1632. 1:03:53so yes typically it holds where
  1633. 1:03:55sometimes it breaks down a little bit
  1634. 1:03:58is at the very upper end you know so
  1635. 1:04:01there's some if you look say at the top
  1636. 1:04:03three or top four cities across the
  1637. 1:04:06in different countries it's not obvious
  1638. 1:04:08that zips law
  1639. 1:04:09holds there you know you have some
  1640. 1:04:12countries where the
  1641. 1:04:13where the biggest city really has say
  1642. 1:04:15half of the population
  1643. 1:04:17and then the ones that kind of fall
  1644. 1:04:19below that
  1645. 1:04:20uh don't quite uh you know so so the
  1646. 1:04:24at the very upper tail it doesn't
  1647. 1:04:26doesn't necess doesn't necessarily hold
  1648. 1:04:28ziploc
  1649. 1:04:28but but let's say in in the model that
  1650. 1:04:30we present
  1651. 1:04:31there's nothing that that generates
  1652. 1:04:34zips law i'm just more talking about
  1653. 1:04:37does it hold in the data
  1654. 1:04:39right there's there's nothing in the
  1655. 1:04:40model because the model is not really a
  1656. 1:04:42model of
  1657. 1:04:43of of dynamics right so so
  1658. 1:04:47there's lots of interesting models that
  1659. 1:04:49urban models that
  1660. 1:04:51generate zips law you know they sort of
  1661. 1:04:53have a model where
  1662. 1:04:54there's particular shocks that happen
  1663. 1:04:56and these shocks over time
  1664. 1:04:58lead to a city-sized distribution that
  1665. 1:05:01that actually satisfies
  1666. 1:05:03zip's law this this is a very
  1667. 1:05:05interesting literature as well and
  1668. 1:05:07we should probably let you move ahead
  1669. 1:05:08here yes let me move ahead and
  1670. 1:05:11i just want to in the second part in the
  1671. 1:05:13remaining 10 or 12 minutes that i have
  1672. 1:05:16i want to mention a couple of other
  1673. 1:05:18issues in urban
  1674. 1:05:20economics and development just to
  1675. 1:05:21broaden the discussion a little bit
  1676. 1:05:23okay so uh
  1677. 1:05:27so let me start with a handbook chapter
  1678. 1:05:30that i wrote with vern henderson a
  1679. 1:05:34couple of years ago
  1680. 1:05:35where we kind of look at the question of
  1681. 1:05:38what do we know
  1682. 1:05:39about the spatial distribution of
  1683. 1:05:41population
  1684. 1:05:42and how that changes with development
  1685. 1:05:46and so one approach that we'll be very
  1686. 1:05:49familiar with you
  1687. 1:05:50for you because you've studied a
  1688. 1:05:52structural transformation in so much
  1689. 1:05:54detail
  1690. 1:05:55over the past weeks and months
  1691. 1:05:59is there there's there's models where we
  1692. 1:06:02say okay
  1693. 1:06:03if the income elasticity for food is
  1694. 1:06:06less than one
  1695. 1:06:07then of course development will lead to
  1696. 1:06:11industrialization
  1697. 1:06:12right and when development leads to
  1698. 1:06:15industrialization
  1699. 1:06:17then kind of that also implies
  1700. 1:06:20urbanization
  1701. 1:06:21to the extent that industry tends to be
  1702. 1:06:23more urbanized than agriculture
  1703. 1:06:25right of course another approach which
  1704. 1:06:28you're also familiar with from your
  1705. 1:06:29classes on
  1706. 1:06:31structural transformation is you can
  1707. 1:06:34make the assumption that the elasticity
  1708. 1:06:36between food and non-food is less than
  1709. 1:06:38one
  1710. 1:06:38in that case industrialization
  1711. 1:06:42results from higher productivity growth
  1712. 1:06:45and agriculture
  1713. 1:06:46and so uh that kind of uh
  1714. 1:06:50that kind of means that to have an to
  1715. 1:06:54have
  1716. 1:06:54industrialization or to have an
  1717. 1:06:56industrial revolution if you wish
  1718. 1:06:58you need to first have an agricultural
  1719. 1:07:00revolution
  1720. 1:07:01right and so you get you get
  1721. 1:07:03productivity growth in agriculture that
  1722. 1:07:05moves people into dust industry an
  1723. 1:07:08industry
  1724. 1:07:09is simply more urbanized than
  1725. 1:07:11agriculture and that's partly because
  1726. 1:07:14of course industry is less land
  1727. 1:07:16intensive right
  1728. 1:07:18so it tends to be more concentrated and
  1729. 1:07:21secondly it may also be more
  1730. 1:07:23concentrated because there's more
  1731. 1:07:26benefits
  1732. 1:07:27from proximity in industry than there is
  1733. 1:07:30in in agriculture okay
  1734. 1:07:34now if you move a little bit forward and
  1735. 1:07:36say what has happened in
  1736. 1:07:38say the last decades in the u.s and in
  1737. 1:07:41some other
  1738. 1:07:42developed countries what we see is that
  1739. 1:07:46although industry yes urbanized
  1740. 1:07:50in the early time period if you look
  1741. 1:07:53more recently
  1742. 1:07:54we see growing spatial dispersion of
  1743. 1:07:58manufacturing
  1744. 1:07:59manufacturing is still relatively
  1745. 1:08:01concentrated but it's becoming less
  1746. 1:08:02concentrated across space across
  1747. 1:08:04over time whereas with services we're
  1748. 1:08:07seeing the opposite
  1749. 1:08:08right services typically used to be sort
  1750. 1:08:11of the industry as you know which was
  1751. 1:08:13non-tradable and you know wherever
  1752. 1:08:14people live
  1753. 1:08:16where wherever people live you have
  1754. 1:08:17services so services extremely spread
  1755. 1:08:19across space
  1756. 1:08:20but we see growing spatial concentration
  1757. 1:08:24of services and again that that may be
  1758. 1:08:27related to land intensity
  1759. 1:08:30which i said was lower in manufacturing
  1760. 1:08:32than in agriculture but it's of course
  1761. 1:08:34even lower
  1762. 1:08:35in services than it is in industry and
  1763. 1:08:38so
  1764. 1:08:38services are displacing manufacturing
  1765. 1:08:41in cities and then manufacturing is
  1766. 1:08:43becoming geographically more
  1767. 1:08:46dispersed it may also have something to
  1768. 1:08:48do with the life cycle of industries
  1769. 1:08:51right as industry matures
  1770. 1:08:54uh there is less need to be
  1771. 1:08:58close to each other because closeness is
  1772. 1:09:00particularly important in the
  1773. 1:09:02when you're learning right when when
  1774. 1:09:05when technology
  1775. 1:09:06is new and there's a lot of innovation
  1776. 1:09:08there's a lot of benefits
  1777. 1:09:09from proximity that maybe that's more
  1778. 1:09:12true now in some service industries than
  1779. 1:09:14it is in
  1780. 1:09:15manufacturing industries and so these
  1781. 1:09:17manufacturing industries
  1782. 1:09:18no longer need to be spatially
  1783. 1:09:20concentrated
  1784. 1:09:21and are dispersing versus services that
  1785. 1:09:24are becoming more
  1786. 1:09:26concentrated and that's a similar
  1787. 1:09:28pattern you know we looked at this in
  1788. 1:09:30the u.s and we've looked at this in
  1789. 1:09:32europe
  1790. 1:09:32other people have looked at this in
  1791. 1:09:34other countries for example in korea
  1792. 1:09:36that's something that's very well
  1793. 1:09:37documented so when industrialization
  1794. 1:09:39happened in korea
  1795. 1:09:41seoul was the main manufacturing center
  1796. 1:09:44uh in the last decades that's no longer
  1797. 1:09:46true
  1798. 1:09:47what we've seen is industry moving out
  1799. 1:09:50of seoul
  1800. 1:09:50into into uh other areas
  1801. 1:09:54um okay now let me uh
  1802. 1:09:57switch quickly to something else here i
  1803. 1:10:00just want to uh
  1804. 1:10:02very briefly discuss a paper by by doug
  1805. 1:10:05and uh remy genwa bandits fall route
  1806. 1:10:09who looked at this at this very
  1807. 1:10:12interesting observation
  1808. 1:10:13right where you know as i said in the
  1809. 1:10:15previous slides
  1810. 1:10:17the the standard the standard view has
  1811. 1:10:20been
  1812. 1:10:21development leads to industrialization
  1813. 1:10:23industrialization
  1814. 1:10:25implies urbanization what they
  1815. 1:10:27documented in a paper is that
  1816. 1:10:30there are many places in africa
  1817. 1:10:34and in the middle east where we see huge
  1818. 1:10:37increases in urbanization
  1819. 1:10:39without seeing big increases in
  1820. 1:10:41industrialization
  1821. 1:10:42and and and the way they explain this is
  1822. 1:10:45that what really matters for
  1823. 1:10:48urbanization is growing income right
  1824. 1:10:51and growing income does not necessarily
  1825. 1:10:54have to come from industrialization
  1826. 1:10:56growing income could also come for
  1827. 1:10:57instance from having a
  1828. 1:10:59higher income from natural resources and
  1829. 1:11:01so the sort of idea
  1830. 1:11:03is that okay we have natural resources
  1831. 1:11:06say
  1832. 1:11:06gas or oil our income goes up
  1833. 1:11:11we're not industrializing but as our
  1834. 1:11:13income improves
  1835. 1:11:14and grows we want to spend our income on
  1836. 1:11:17stuff
  1837. 1:11:18right and we want to live in a city uh
  1838. 1:11:21to enjoy the city
  1839. 1:11:22to be able to spend money in the city
  1840. 1:11:24and so this is kind of the idea that
  1841. 1:11:27when we think about cities and
  1842. 1:11:29development
  1843. 1:11:30we shouldn't think only about cities and
  1844. 1:11:33development
  1845. 1:11:35cities being productive centers
  1846. 1:11:38cities are also consumption centers
  1847. 1:11:40right and
  1848. 1:11:41and that's true in some of these places
  1849. 1:11:43in africa in the middle east
  1850. 1:11:44it's it's actually also true in some of
  1851. 1:11:46uh
  1852. 1:11:47some of the developed countries right i
  1853. 1:11:49mean there's there are many
  1854. 1:11:51people some of the rich people in the
  1855. 1:11:53world
  1856. 1:11:54who want to move to say a city like
  1857. 1:11:56london
  1858. 1:11:57not to be productive they just want to
  1859. 1:11:59live in london to enjoy london
  1860. 1:12:01right of course london is a very
  1861. 1:12:02productive city right because
  1862. 1:12:04lots of people are working there but
  1863. 1:12:06there's a growing uh
  1864. 1:12:08share of the population or just there to
  1865. 1:12:11enjoy the place
  1866. 1:12:12right and so if you have a lot of money
  1867. 1:12:14you also want to spend it where can you
  1868. 1:12:15spend it well you can spend it in
  1869. 1:12:17in some of these uh big big cities
  1870. 1:12:21okay i'm i'm i'm slowly going to um
  1871. 1:12:25be wrapping up here uh but i wanted to
  1872. 1:12:28mention
  1873. 1:12:29just a few more things uh another really
  1874. 1:12:32interesting paper
  1875. 1:12:33uh recent paper on development
  1876. 1:12:37and and space is this paper by henderson
  1877. 1:12:41and others
  1878. 1:12:42in the qje so what they look is what are
  1879. 1:12:45the
  1880. 1:12:45what they look at is what are the
  1881. 1:12:47determinants of the global distribution
  1882. 1:12:49of economic activity
  1883. 1:12:51right and so they look at the entire
  1884. 1:12:53planet and they look
  1885. 1:12:54they use satellite lights right to
  1886. 1:12:56measure the level of development
  1887. 1:12:58or the level of the distribution of
  1888. 1:13:00economic activity across space
  1889. 1:13:02and they say let's kind of look at two
  1890. 1:13:05groups of determinants
  1891. 1:13:07let's think about the permanence that
  1892. 1:13:09are important for agriculture
  1893. 1:13:11so maybe the soil quality or the
  1894. 1:13:14temperature or whatever or the
  1895. 1:13:15precipitation so you look at certain
  1896. 1:13:18factors or determinants that are
  1897. 1:13:19important for agriculture productivity
  1898. 1:13:22and then they look at certain
  1899. 1:13:23determinants that are important for
  1900. 1:13:25trade
  1901. 1:13:26meaning access how well am i connected
  1902. 1:13:30to the rest of the world maybe am i a
  1903. 1:13:32port am i on a big river
  1904. 1:13:34that that facilitates trade and they
  1905. 1:13:36come up
  1906. 1:13:37with a very then they run a bunch of
  1907. 1:13:39regressions but they come up with a very
  1908. 1:13:40puzzling finding
  1909. 1:13:42which is that it turns out
  1910. 1:13:45that agriculture so this group of
  1911. 1:13:47variables which we could call
  1912. 1:13:49agricultural determinants explains much
  1913. 1:13:51more of the variation
  1914. 1:13:54in the spatial distribution of economic
  1915. 1:13:57activity
  1916. 1:13:58in developed countries than in
  1917. 1:13:59developing countries
  1918. 1:14:01it's puzzling in the sense that you
  1919. 1:14:03would say well in developed countries
  1920. 1:14:05nobody is doing agriculture anymore
  1921. 1:14:07how come agriculture seems to determine
  1922. 1:14:09where people live
  1923. 1:14:10and i go to developing countries but
  1924. 1:14:12agriculture is still very important
  1925. 1:14:14and there it matters a lot less than in
  1926. 1:14:16developed countries
  1927. 1:14:17and so the explanation they come up with
  1928. 1:14:20is that
  1929. 1:14:21in the early developers let's say
  1930. 1:14:24today's advanced economies
  1931. 1:14:26structural transformation out of
  1932. 1:14:29agriculture into industry
  1933. 1:14:31happened at a time when transportation
  1934. 1:14:34costs were still very high
  1935. 1:14:36and and that means that at that time
  1936. 1:14:39cities
  1937. 1:14:40tended to be located in agriculture
  1938. 1:14:43regions right
  1939. 1:14:44so just sort of go back 200 or 300 years
  1940. 1:14:47right and think about it in the
  1941. 1:14:49following way
  1942. 1:14:51where did cities grow cities grew in
  1943. 1:14:53places where it was agricultural surplus
  1944. 1:14:56right so that there was enough to eat
  1945. 1:14:58for everyone
  1946. 1:14:59and some people could start doing other
  1947. 1:15:01stuff so they moved into cities
  1948. 1:15:04to dedicate themselves to other
  1949. 1:15:06productive activities
  1950. 1:15:07but of course once they were in these
  1951. 1:15:09cities they still needed to eat
  1952. 1:15:10right and so where did they get the food
  1953. 1:15:12from they sourced that food
  1954. 1:15:14locally right and
  1955. 1:15:18and they had to source it locally
  1956. 1:15:20because transportation costs were still
  1957. 1:15:22very high
  1958. 1:15:23and so the point is that in advanced
  1959. 1:15:26economies
  1960. 1:15:27cities tended to emerge in places that
  1961. 1:15:30had a productive agricultural hinterland
  1962. 1:15:33versus in less developed countries or
  1963. 1:15:36later developers if you wish
  1964. 1:15:38where trade was already relatively cheap
  1965. 1:15:42that wasn't really needed and so cities
  1966. 1:15:44could emerge
  1967. 1:15:45in places that didn't necessarily have
  1968. 1:15:47have have an agricultural hinterland
  1969. 1:15:50let me wrap up with one last thought
  1970. 1:15:53here
  1971. 1:15:54uh related to a space and
  1972. 1:15:57sector of specialization etc um
  1973. 1:16:00i will just take one minute i realize
  1974. 1:16:03i'm going a little bit over time here
  1975. 1:16:05but i've been working in the last years
  1976. 1:16:07quite a bit
  1977. 1:16:09on models uh spatial models
  1978. 1:16:13of uh climate change right and so
  1979. 1:16:17why is that interesting in the context
  1980. 1:16:19of
  1981. 1:16:20this course i think well of course
  1982. 1:16:22because
  1983. 1:16:24on the one hand you need to think about
  1984. 1:16:26space
  1985. 1:16:27because different places are going to be
  1986. 1:16:29affected differently
  1987. 1:16:31by global warming but you also need to
  1988. 1:16:34think about sectors
  1989. 1:16:35because obviously agriculture depending
  1990. 1:16:38on where you are
  1991. 1:16:39may be much more affected by global
  1992. 1:16:41warming than other sectors
  1993. 1:16:43right and so we will see big
  1994. 1:16:46shifts in where different things
  1995. 1:16:50are going to be produced
  1996. 1:16:53because of because of climate shocks
  1997. 1:16:56right and so we can look at
  1998. 1:16:57you know different maps and we can do
  1999. 1:16:59different things
  2000. 1:17:00with these types of models on you know
  2001. 1:17:03here this last thing here is
  2002. 1:17:05looking at uh in the earth 2200
  2003. 1:17:10where when agric cultural output
  2004. 1:17:12happened this is part b
  2005. 1:17:15in in a world without climate change
  2006. 1:17:17versus in a world with climate change
  2007. 1:17:19which would be c
  2008. 1:17:21so so that's very interesting i think as
  2009. 1:17:23well sort of thinking about
  2010. 1:17:24not just urban and space but think
  2011. 1:17:28urban space plus sectors right
  2012. 1:17:30agriculture versus other sectors
  2013. 1:17:32how that might be impacted by climate
  2014. 1:17:35change
  2015. 1:17:36i'm going to stop here i went a little
  2016. 1:17:38bit over time and i'm happy to take
  2017. 1:17:41any questions you might have
  2018. 1:17:45fantastic thanks a ton klaus um
  2019. 1:17:48let me open things up to the front row
  2020. 1:17:50first
  2021. 1:17:54hi close thanks for the presentation
  2022. 1:17:57really interesting
  2023. 1:17:58um going back to the that first model
  2024. 1:18:01where you have the ait
  2025. 1:18:02term for cities i guess how would you
  2026. 1:18:06think about making it endogenous because
  2027. 1:18:08i could imagine so
  2028. 1:18:09actually one thing we we did do and i
  2029. 1:18:12didn't mention
  2030. 1:18:13uh we did a number of exercises where we
  2031. 1:18:17endogenized aid in the following sense
  2032. 1:18:21as you know in in urban economics and in
  2033. 1:18:23economic geography
  2034. 1:18:26there is a lot of evidence that
  2035. 1:18:29ait is made up of two components
  2036. 1:18:33one is kind of exogenously given
  2037. 1:18:37maybe relates to one of the questions we
  2038. 1:18:39had before
  2039. 1:18:40you know maybe you know you have better
  2040. 1:18:42amenities so you have
  2041. 1:18:43you have better endowments or you're in
  2042. 1:18:46a more favorable location
  2043. 1:18:48we could think of that as being
  2044. 1:18:50exogenous and then
  2045. 1:18:51an endogenous component that is related
  2046. 1:18:56to size right so bigger cities
  2047. 1:19:00uh tend to be more efficient because
  2048. 1:19:03they're bigger
  2049. 1:19:04right and there's a lot of estimates out
  2050. 1:19:06there and typically the estimates
  2051. 1:19:08range somewhere between an elasticity of
  2052. 1:19:11somewhere between
  2053. 1:19:13point zero two and point zero six
  2054. 1:19:16meaning
  2055. 1:19:17when you double a a city in size
  2056. 1:19:20the productivity would go up by
  2057. 1:19:23somewhere between
  2058. 1:19:24two and six percent so so that's the way
  2059. 1:19:26in which we endogenize
  2060. 1:19:28the ait you could of course go to a
  2061. 1:19:31fully
  2062. 1:19:32dynamic model in which you also
  2063. 1:19:35think about innovation and incentives to
  2064. 1:19:38innovate
  2065. 1:19:39and how that may be different across the
  2066. 1:19:42cities because different cities have
  2067. 1:19:44different markets
  2068. 1:19:45and if i'm in a bigger market i may have
  2069. 1:19:47a
  2070. 1:19:48greater incentive to uh to engage in
  2071. 1:19:50local innovation
  2072. 1:19:52uh that is actually this last couple of
  2073. 1:19:55slides that i showed you
  2074. 1:19:56these models with climate change uh
  2075. 1:19:58actually also
  2076. 1:20:00those are fully dynamic and look at at
  2077. 1:20:03the
  2078. 1:20:03incentives to innovate in in the in the
  2079. 1:20:06paper on urban
  2080. 1:20:07with the ait there we endogenize
  2081. 1:20:11simply in terms of bringing in city size
  2082. 1:20:15as an additional determinant of city
  2083. 1:20:18productivity
  2084. 1:20:21thank you yeah
  2085. 1:20:24that was a question from stephen barlow
  2086. 1:20:27in the q a
  2087. 1:20:28really kind of a complex of questions
  2088. 1:20:31about
  2089. 1:20:32covin and um
  2090. 1:20:35the extent to which we may be seeing a
  2091. 1:20:38change in the pattern of people working
  2092. 1:20:39in city centers
  2093. 1:20:41how much does that motivate a rethinking
  2094. 1:20:44of the standard urban model
  2095. 1:20:47so that that's a really fascinating
  2096. 1:20:50question
  2097. 1:20:51and and now we'll answer it maybe in two
  2098. 1:20:53different ways so
  2099. 1:20:55um i was recently reading a paper by
  2100. 1:20:59nick bloom and some other people at
  2101. 1:21:01stanford
  2102. 1:21:02about you know will will work at home
  2103. 1:21:06will that stay or will it not stay and i
  2104. 1:21:08think they come up with some kind of
  2105. 1:21:10number that
  2106. 1:21:11probably uh 20 percent uh
  2107. 1:21:14they will 20 of work will be done from
  2108. 1:21:17home uh
  2109. 1:21:18now the very important question when we
  2110. 1:21:20say 20
  2111. 1:21:21just to say a number right suppose we
  2112. 1:21:23say 20 will will be done from home
  2113. 1:21:26it's very different if you say
  2114. 1:21:29every individual will say work
  2115. 1:21:33four days in the office and one day at
  2116. 1:21:36home
  2117. 1:21:37versus saying 80 of the individuals
  2118. 1:21:41will work five days a week in the office
  2119. 1:21:43and twenty percent of the individuals
  2120. 1:21:45were work
  2121. 1:21:46all five days from home uh if you take
  2122. 1:21:49those two
  2123. 1:21:50uh cases they would have very very
  2124. 1:21:53different implications
  2125. 1:21:54for uh for city sizes right and for the
  2126. 1:21:58urban model so
  2127. 1:21:59if if i take the second case which i
  2128. 1:22:02sort of feel is a more reasonable one
  2129. 1:22:03but i'm not 100 sure
  2130. 1:22:05if you sort of say we'll move to a model
  2131. 1:22:07where
  2132. 1:22:08many people will work one day a week or
  2133. 1:22:11maybe two days a week from home
  2134. 1:22:14then you could imagine that cities may
  2135. 1:22:16actually become a lot larger
  2136. 1:22:18right because the easiest way of
  2137. 1:22:20modeling that would simply to say look
  2138. 1:22:22my commuting costs are going to go down
  2139. 1:22:24by 20 or my 40 percent
  2140. 1:22:26and you know if i need to commute every
  2141. 1:22:28day an hour in
  2142. 1:22:30an hour out that's too much i mean the
  2143. 1:22:33average commute in america is about
  2144. 1:22:3530 minutes in and 30 minutes out it
  2145. 1:22:38seems like
  2146. 1:22:39more than 30 minutes people don't have a
  2147. 1:22:40lot of patience for that
  2148. 1:22:42but but if you only have to do this
  2149. 1:22:43three days a week
  2150. 1:22:45you may be perfectly happy with 45 60
  2151. 1:22:47minutes
  2152. 1:22:48it's okay right if you do this three
  2153. 1:22:49days a week and so cities could actually
  2154. 1:22:52become
  2155. 1:22:52a lot larger because the urban costs are
  2156. 1:22:56going down because you
  2157. 1:22:57don't need to do it every eve every day
  2158. 1:23:00versus
  2159. 1:23:01the other model where you say no no this
  2160. 1:23:04is going to be 20 of people who will
  2161. 1:23:06never go into the office
  2162. 1:23:08well then of course those those 20
  2163. 1:23:10become completely footloose
  2164. 1:23:12they could be anywhere right and we've
  2165. 1:23:14always had some
  2166. 1:23:15part of the labor force you know people
  2167. 1:23:17working you know as
  2168. 1:23:18telephone uh how i answered telephones
  2169. 1:23:20and customer service
  2170. 1:23:22they may just be living in a small city
  2171. 1:23:24somewhere in uh
  2172. 1:23:26in anywhere really right and they don't
  2173. 1:23:28need
  2174. 1:23:29they don't need any of that urban urban
  2175. 1:23:32they don't need any of that urban
  2176. 1:23:33environment so
  2177. 1:23:34so depending on where we're heading the
  2178. 1:23:38the the the the effects may be quite
  2179. 1:23:41different
  2180. 1:23:42another another small
  2181. 1:23:45thing related to covet is
  2182. 1:23:48there is some evidence
  2183. 1:23:52that there is again a growing demand
  2184. 1:23:56for living in the suburbs
  2185. 1:23:59because there's growing demand for space
  2186. 1:24:02right and so that may also of course
  2187. 1:24:05change the structure of cities
  2188. 1:24:07right in the following sense in our
  2189. 1:24:10model
  2190. 1:24:10i made the assumption that every
  2191. 1:24:13individual lives on one unit of land
  2192. 1:24:16that's obviously a simplifying
  2193. 1:24:17assumption right it's true that
  2194. 1:24:20as you move away from the city center
  2195. 1:24:23people tend to live on bigger and bigger
  2196. 1:24:25plots of land
  2197. 1:24:26right if you bring that into the model
  2198. 1:24:29and if you start thinking that
  2199. 1:24:31the demand for space there's a shock to
  2200. 1:24:34the demand for space
  2201. 1:24:36because i'm going to be working more at
  2202. 1:24:37home for example right
  2203. 1:24:39i need some more space if i'm going to
  2204. 1:24:41need a home office
  2205. 1:24:43that may change that rent gradient and
  2206. 1:24:46that may change
  2207. 1:24:49the compactness of cities and there may
  2208. 1:24:51be some effects
  2209. 1:24:52there may be some effects there as well
  2210. 1:24:55another
  2211. 1:24:56related and i'll stop here because i
  2212. 1:24:57realize there may be some other
  2213. 1:24:58questions but
  2214. 1:24:59another really interesting uh question
  2215. 1:25:02at least to me is
  2216. 1:25:04what is going to happen to these
  2217. 1:25:07agglomeration economies right
  2218. 1:25:10so so you know if you look at
  2219. 1:25:14agglomeration economies as i said these
  2220. 1:25:16are the conglomerations you get from
  2221. 1:25:17density
  2222. 1:25:18but but we as economists we think of
  2223. 1:25:20those economies as being external
  2224. 1:25:23right they're externalities they're
  2225. 1:25:25external to the individual
  2226. 1:25:26they may even be external to the firm so
  2227. 1:25:29if you allow
  2228. 1:25:30individuals to choose whether they go to
  2229. 1:25:33work
  2230. 1:25:34or not go to work or even if you allow
  2231. 1:25:36firms to tell people what they should do
  2232. 1:25:39right those decision makers are not
  2233. 1:25:42fully internalizing
  2234. 1:25:44these agglomeration economies so there
  2235. 1:25:47may be some
  2236. 1:25:49there may be some bad surprises in terms
  2237. 1:25:52of productivity if
  2238. 1:25:54if this is taken to an extreme the
  2239. 1:25:56example would be
  2240. 1:25:57suppose we now all change our
  2241. 1:26:00preferences
  2242. 1:26:00and we all want to stay at home always
  2243. 1:26:03right
  2244. 1:26:05you know it's a very big question what
  2245. 1:26:07would happen to these agglomeration
  2246. 1:26:09economies
  2247. 1:26:10right and i think that's a fascinating
  2248. 1:26:12question and and
  2249. 1:26:14and it's not obvious that that the
  2250. 1:26:16so-called decentralized economy
  2251. 1:26:19will bring us to a place that's
  2252. 1:26:23uh that's good we don't really know
  2253. 1:26:25what's going to happen to that
  2254. 1:26:29any other questions yeah i wanted to ask
  2255. 1:26:33you a quick question
  2256. 1:26:34um actually it's it's sort of true so
  2257. 1:26:37one was a more general question because
  2258. 1:26:39you were saying in on the first part as
  2259. 1:26:41well that
  2260. 1:26:42yeah you don't even need that much data
  2261. 1:26:44to make great analysis using that simple
  2262. 1:26:46model
  2263. 1:26:47but um this said is there any like very
  2264. 1:26:50innovative or interesting data source
  2265. 1:26:53for um
  2266. 1:26:54yeah in the context of urbanization you
  2267. 1:26:56would like
  2268. 1:26:57be able to point out to us um yeah and
  2269. 1:27:00the second
  2270. 1:27:01and the second question i have was
  2271. 1:27:02referring also to this first model
  2272. 1:27:05yeah where it's not entirely clear to me
  2273. 1:27:07how um
  2274. 1:27:08maybe different yeah costs of
  2275. 1:27:12of actual goods in the city might enter
  2276. 1:27:15like
  2277. 1:27:15how differences in prices and not just
  2278. 1:27:17trends
  2279. 1:27:19enter into that model and how they
  2280. 1:27:21matter
  2281. 1:27:23and thank you very much for this awesome
  2282. 1:27:24presentation yes thank you
  2283. 1:27:27so your first question is a fantastic
  2284. 1:27:30question
  2285. 1:27:31and i don't have a very good answer but
  2286. 1:27:34what i
  2287. 1:27:35do what i what i what i can say
  2288. 1:27:38is that the world of
  2289. 1:27:41spatial data is really
  2290. 1:27:44exploding right and so there's
  2291. 1:27:48more and more information available
  2292. 1:27:52at the local level and and people are
  2293. 1:27:55using uh
  2294. 1:27:57very creative ways of
  2295. 1:28:00getting at these data right so so of
  2296. 1:28:02course the one example is using
  2297. 1:28:04satellite data to
  2298. 1:28:06to measure uh local economic activity
  2299. 1:28:10but there's also people who have looked
  2300. 1:28:12at
  2301. 1:28:14at more who've looked at for example
  2302. 1:28:19data on parking lots of
  2303. 1:28:23shopping malls to try to understand the
  2304. 1:28:26retail activity at the local level you
  2305. 1:28:28know how full are those parking lots and
  2306. 1:28:30how
  2307. 1:28:31what does that tell me about uh about uh
  2308. 1:28:35the economic cycle so so so there's more
  2309. 1:28:37and more data
  2310. 1:28:39available at uh at the local level
  2311. 1:28:42uh and and it's really an exploding
  2312. 1:28:45field so i think
  2313. 1:28:46uh doing stuff uh doing spatial
  2314. 1:28:49economics in general is is
  2315. 1:28:52is interesting because there's lots of
  2316. 1:28:53of course interesting questions but
  2317. 1:28:55it's also promising this promising field
  2318. 1:28:58because
  2319. 1:28:59the data are just uh getting better and
  2320. 1:29:02better
  2321. 1:29:03uh over time right and so i think it
  2322. 1:29:06it still requires some doses of
  2323. 1:29:10creativity but when you kind of look
  2324. 1:29:13around
  2325. 1:29:14and you look at how people are creative
  2326. 1:29:16it's really quite
  2327. 1:29:18quite amazing there was recently
  2328. 1:29:21a paper i don't remember where it was
  2329. 1:29:23published
  2330. 1:29:24by some economists uh
  2331. 1:29:28looking at how we can use uh historical
  2332. 1:29:31spatial data to
  2333. 1:29:33think about some of the big questions of
  2334. 1:29:35economic history
  2335. 1:29:37right and so people are using all kinds
  2336. 1:29:39of map
  2337. 1:29:40technologies and all kinds of ways of
  2338. 1:29:43trying to get the information at the
  2339. 1:29:46local level
  2340. 1:29:47you know even going back to say 19 18th
  2341. 1:29:49century
  2342. 1:29:51so it's a it's a very it's it's a very
  2343. 1:29:53uh
  2344. 1:29:55it's a very exciting uh it's a very
  2345. 1:29:57exciting field
  2346. 1:29:59to to be in uh your second question on
  2347. 1:30:03on prices in general i think there's two
  2348. 1:30:07things here one is
  2349. 1:30:08uh in general uh we all know that
  2350. 1:30:13in bigger cities there is more
  2351. 1:30:15competition for land
  2352. 1:30:17and so land prices go up and that
  2353. 1:30:19translates into
  2354. 1:30:20higher housing prices but it just
  2355. 1:30:24typically also translated to higher
  2356. 1:30:26prices in general
  2357. 1:30:28and so a lot of urban economists
  2358. 1:30:31kind of simplify things and just focus
  2359. 1:30:34on
  2360. 1:30:35on house prices as a kind of proxy a
  2361. 1:30:39kind of all-encompassing proxy
  2362. 1:30:41of measuring uh the cost of density that
  2363. 1:30:44that goes to through the lamp price uh
  2364. 1:30:48but but but you're right with that not
  2365. 1:30:50everything is said
  2366. 1:30:51right there's also evidence for instance
  2367. 1:30:53that bigger cities
  2368. 1:30:56uh uh have more competition
  2369. 1:30:59right so because they have more
  2370. 1:31:00competition the prices of certain things
  2371. 1:31:03may actually also be lower
  2372. 1:31:04right so land prices are higher but it
  2373. 1:31:07that doesn't mean that the price of
  2374. 1:31:08every single
  2375. 1:31:09uh product you buy is necessarily higher
  2376. 1:31:12so
  2377. 1:31:13so there's also fascinating literature i
  2378. 1:31:15think on
  2379. 1:31:16on size of market size of local market
  2380. 1:31:19degree of competition how that feeds
  2381. 1:31:22into prices how that feeds into uh
  2382. 1:31:24innovation etc etc
  2383. 1:31:31any uh any other questions
  2384. 1:31:34i have a quick one for you i think it's
  2385. 1:31:36a quick one from
  2386. 1:31:37somash mature in the in the q a do we
  2387. 1:31:40have some better indices
  2388. 1:31:42than um then
  2389. 1:31:46indices of spatial dispersion so um
  2390. 1:31:48obviously hirschmann her selector
  2391. 1:31:50um but what kind of indices do we have
  2392. 1:31:54of dispersion among manufacturing
  2393. 1:31:56services that
  2394. 1:31:57are useful looking at locations
  2395. 1:32:01so i would say two things so if you just
  2396. 1:32:03want to have
  2397. 1:32:04one statistic
  2398. 1:32:08yes so you know you'll use the the
  2399. 1:32:11herschleifer index you can look at uh
  2400. 1:32:14and of course the variance or the
  2401. 1:32:16coefficient of variation
  2402. 1:32:18or the difference between the 80th and
  2403. 1:32:20the 20th percentile so
  2404. 1:32:22all the sort of standard all all the
  2405. 1:32:25sort of standard measures
  2406. 1:32:27but i'll but but what is true as well is
  2407. 1:32:29that
  2408. 1:32:30sometimes it is actually useful to look
  2409. 1:32:33at the entire distribution
  2410. 1:32:35right and so you may sometimes be
  2411. 1:32:37surprised you may think well
  2412. 1:32:38everything is said by increasing or
  2413. 1:32:40decreasing dispersion
  2414. 1:32:42but when you look at the entire
  2415. 1:32:44distribution uh
  2416. 1:32:46you may see some things you you didn't
  2417. 1:32:50expect
  2418. 1:32:50right so it may very well be that that
  2419. 1:32:53for example again that
  2420. 1:32:55that maybe these medium-sized places are
  2421. 1:32:58uh
  2422. 1:32:59are becoming uh are doing particularly
  2423. 1:33:02well
  2424. 1:33:02and that the the both the biggest and
  2425. 1:33:05the smallest and
  2426. 1:33:06the medium small are not doing that well
  2427. 1:33:08so so i would always
  2428. 1:33:10recommend to the extent possible rather
  2429. 1:33:13than immediately going
  2430. 1:33:15to a summary statistic like the ones we
  2431. 1:33:19mentioned
  2432. 1:33:20that i would i would plot the entire
  2433. 1:33:22distribution
  2434. 1:33:23just to see hey is there anything else
  2435. 1:33:25that's interesting so you could for
  2436. 1:33:26example have a situation where the tail
  2437. 1:33:29is becoming a lot fatter or where the
  2438. 1:33:31tail is not become
  2439. 1:33:32where the tail is becoming thinner maybe
  2440. 1:33:34maybe the action is over there
  2441. 1:33:36right and then maybe looking at
  2442. 1:33:38dispersion or concentration is not
  2443. 1:33:40really the right way of
  2444. 1:33:42looking at the data right and so that's
  2445. 1:33:44that would be my
  2446. 1:33:45that would be my recommendation
  2447. 1:33:49i think i should probably in the
  2448. 1:33:51interest of time there's
  2449. 1:33:52there's still always last questions
  2450. 1:33:55coming in but i think in the interest of
  2451. 1:33:57time we should probably close things out
  2452. 1:33:59and so i'd like to thank you klaus and
  2453. 1:34:02i'd also like to turn things over
  2454. 1:34:04to my my partner in crime joe kaboski
  2455. 1:34:07to close out today's lecture and and
  2456. 1:34:09really i guess to close out the whole
  2457. 1:34:11set of lectures so my thanks klaus and
  2458. 1:34:14maybe others can join me first
  2459. 1:34:16before i turn it over to joe maybe those
  2460. 1:34:19in the front row can do what we've been
  2461. 1:34:20doing and unmute
  2462. 1:34:21and let's give klaus uh a round of um
  2463. 1:34:25real as close to real applause as we can
  2464. 1:34:32yeah thank you all it was it was it was
  2465. 1:34:35really fun and i
  2466. 1:34:36i enjoyed it and very good questions too
  2467. 1:34:38i i always worry in these types of
  2468. 1:34:41online settings where there's lots of
  2469. 1:34:43people uh
  2470. 1:34:45how do you get to a good level of
  2471. 1:34:48engagement and interaction and i'm very
  2472. 1:34:50happy that this part this part just
  2473. 1:34:53worked really well so thank you
  2474. 1:34:55thanks and and joe let me turn things
  2475. 1:34:57over to you
  2476. 1:34:58yeah that's a great segue into uh what i
  2477. 1:35:01wanted to say
  2478. 1:35:01i mean the first is that this is the
  2479. 1:35:03last uh lecture of the course
  2480. 1:35:05um uh klaus was the headliner cleanup
  2481. 1:35:09batter and um so i wanted to thank the
  2482. 1:35:12cepr staff
  2483. 1:35:14especially for you know everything that
  2484. 1:35:16they've done
  2485. 1:35:17making this possible uh that's um
  2486. 1:35:21mandy chan kirsty mcneil mcneil
  2487. 1:35:25lauren waring and nadine clark um
  2488. 1:35:28and people you know all through uh cepr
  2489. 1:35:33um this course has really been a
  2490. 1:35:36grand experiment uh not only for cepr
  2491. 1:35:40but i think for the profession
  2492. 1:35:42i know that um next week i'm meeting
  2493. 1:35:45with people for bread
  2494. 1:35:46to try to figure out a similar type of a
  2495. 1:35:50course
  2496. 1:35:50so that we can reach more people um
  2497. 1:35:53i it's in in our minds in doug's and
  2498. 1:35:57in my mind it's been a tremendous
  2499. 1:35:58success i've learned a ton
  2500. 1:36:00uh just from sitting in on these
  2501. 1:36:01lectures um
  2502. 1:36:04but we want to learn more and we'd like
  2503. 1:36:06to get feedback from the students
  2504. 1:36:08so we will be sending out uh and and
  2505. 1:36:10maybe as well from the
  2506. 1:36:12lecturers uh we will be sending out
  2507. 1:36:15an evaluation uh i think
  2508. 1:36:18both uh maybe with an anonymous part and
  2509. 1:36:21a uh identified part because
  2510. 1:36:25we'd also like to sell the idea and so
  2511. 1:36:27if we can get some nice quotes
  2512. 1:36:30with names attached that would be
  2513. 1:36:32wonderful
  2514. 1:36:34but we also want to learn how to improve
  2515. 1:36:35the course
  2516. 1:36:37are there ways to like klaus said are
  2517. 1:36:39there ways to improve
  2518. 1:36:40engagement um we we need to find out uh
  2519. 1:36:44you know
  2520. 1:36:45where things went right and where they
  2521. 1:36:46went wrong so i just want to thank you
  2522. 1:36:48all
  2523. 1:36:49of course it's you know always the
  2524. 1:36:51people that hang out until the very end
  2525. 1:36:52are
  2526. 1:36:53only a fraction of the overall people um
  2527. 1:36:56but i want to thank you guys especially
  2528. 1:36:59and
  2529. 1:36:59uh please give us feedback so we can
  2530. 1:37:01learn from this
  2531. 1:37:03thanks klaus as well bye-bye
  2532. 1:37:12thanks everyone we look forward to
  2533. 1:37:14hearing from you all
  2534. 1:37:15and to staying in touch so many many
  2535. 1:37:18thanks
  2536. 1:37:20all the students all the people who've
  2537. 1:37:21been attending it's
  2538. 1:37:23it's uh it's been great to get to know
  2539. 1:37:25many of you over the past weeks too
  2540. 1:37:28so look forward to staying in touch
  2541. 1:37:33bye everyone
  2542. 1:38:34you

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