Supplemental lecture: Urbanization and development — Transcript
Full transcript
- 0:28recording
- 0:53right let's go ahead and start good
- 0:56morning good afternoon good evening
- 0:58wherever you are in the world
- 1:00and welcome to all to this the the last
- 1:03actual uh lecture in the stag virtual
- 1:06course on key concepts in macro
- 1:08development
- 1:10today's lecture is a supplemental
- 1:12lecture we're really delighted to have
- 1:14klaus desmond here to talk about
- 1:16urbanization
- 1:17and development it's um wonderful of you
- 1:20to join klaus
- 1:22and this is our 20th lecture
- 1:25it is um really wonderful to see so many
- 1:28people
- 1:29who have stuck with us throughout and
- 1:31i'm delighted to welcome everyone
- 1:34um i'd like to give special thanks
- 1:36before we begin
- 1:38to the team from cepr which has made it
- 1:42possible to put together
- 1:43this lecture series and has done the
- 1:45work behind the scenes
- 1:47um keeping material up on the website
- 1:50we're
- 1:50loading the recordings onto youtube so
- 1:53i'd particularly like to
- 1:54single out mandy chan christy mcneil
- 1:58lauren waring
- 1:59and nadine clark who've done an amazing
- 2:02job and made this
- 2:03and made this work the
- 2:06the course is part of the steg program
- 2:08and as we've said many times before and
- 2:10at the risk of boring those of you who
- 2:12are now hearing this for the 20th time
- 2:14steg is a research program steg stands
- 2:17for structural transformation
- 2:18and economic growth it's a research
- 2:21program
- 2:22funded by the united kingdom's foreign
- 2:24commonwealth
- 2:25and development office as part of the uk
- 2:288 effort it's managed by cepr in london
- 2:32and we've just been really very
- 2:35fortunate to find
- 2:36colleagues across the profession who've
- 2:38been willing to contribute
- 2:40lectures to this series and to put a
- 2:43stock of knowledge out there that we
- 2:45hoped would
- 2:46lay a groundwork for doctoral level
- 2:48teaching
- 2:49on this topic which isn't really offered
- 2:51in any one institution
- 2:53and so um this lecture fits in perfectly
- 2:57the question of how
- 2:58urbanization relates to development is
- 3:00one that's obviously
- 3:01really fundamental to the processes of
- 3:04structural change and sectoral
- 3:06movements before i turn things over to
- 3:09klaus i just want to reiterate some of
- 3:10the ground rules which will also be
- 3:12familiar
- 3:13to all of you those of you in the
- 3:15virtual front row will control your own
- 3:17cameras and microphones
- 3:19klaus says you're more than willing to
- 3:21interrupt with questions
- 3:23as he goes along please feel free don't
- 3:25be shy
- 3:26for those of you who are not in the
- 3:28front row
- 3:29the way for you to ask questions is to
- 3:32pose them
- 3:32in the q a section so use that feature
- 3:37um klaus won't be able to see those
- 3:39questions but i and joe kaboski will do
- 3:42our best to answer as many of those
- 3:43questions as we can
- 3:45and the ones that we can't answer that
- 3:47are really hard and difficult
- 3:48we'll hand over to klaus and make him
- 3:50answer um
- 3:52and i think that's i think those are the
- 3:54key bits of information that we need
- 3:57so again without further ado i will turn
- 3:59things over to klaus
- 4:01and please go ahead and share your
- 4:03slides
- 4:04um for those watching the slides are all
- 4:07online i'll
- 4:08i will make sure that the link gets to
- 4:10you and
- 4:12please feel free to follow along klaus
- 4:14over to you
- 4:16thank you uh doug for the kind uh
- 4:18introduction it's uh
- 4:20it's a real pleasure to uh to be here
- 4:23today and uh to be able to talk to
- 4:26uh all of you about this important topic
- 4:29development and urbanization
- 4:33so i will divide
- 4:37my lecture today
- 4:40in two parts most of it
- 4:43i will dedicate to the discussion of
- 4:47one particular paper which i wrote
- 4:51a couple of years ago with a colleague
- 4:55with esteban rossi hamsburg
- 4:58on determinants
- 5:01of the city size distribution
- 5:04in particular in that paper we looked at
- 5:08the role of three important determinants
- 5:12in the city size distribution uh
- 5:15productivity or efficiency amenities
- 5:19and urban frictions and then we apply
- 5:23actually our methodology to look at the
- 5:26us and china
- 5:27and so you could ask yourself uh
- 5:30how is this related to uh
- 5:33to development well of course as you all
- 5:37know
- 5:38uh the development process uh is
- 5:41typically accompanied
- 5:42by um urbanization by people moving from
- 5:47rural areas to uh to cities
- 5:51and that leads to a number of challenges
- 5:54right so for example there's always this
- 5:57big
- 5:57question whether some of the world's
- 6:01mega cities are becoming
- 6:04too big right and this type of approach
- 6:07that i will
- 6:08be talking about to you today will be
- 6:10able to
- 6:12uh give you a framework
- 6:15uh to think about that question and to
- 6:17actually quantitatively
- 6:19assess that question so that's one
- 6:23reason why
- 6:25we think this is important another
- 6:27reason is that
- 6:29as you all know in many many countries
- 6:33uh governments are very worried about
- 6:37the spatial distribution
- 6:39of economic activity right so maybe
- 6:42development is too conscious
- 6:44concentrated in particular areas and
- 6:47they want to
- 6:48spread it over the territory and once
- 6:51again you can ask yourself
- 6:53is that a reasonable policy or is it not
- 6:57you know what are the welfare effects
- 6:59for example of
- 7:00a policy that would uh
- 7:03promote growth in for instance medium
- 7:08medium-sized or small-sized cities is
- 7:11that something that
- 7:12makes sense right so it may make sense
- 7:14from a territorial perspective
- 7:16does it also make sense from a welfare
- 7:18perspective so all these questions one
- 7:20one can ask by by applying the
- 7:23methodology
- 7:25i will be talking about today
- 7:28and then lastly maybe as as part of the
- 7:30motivation
- 7:32is that we think there's a lot of value
- 7:36in comparing urban systems
- 7:40uh across countries right so as i said
- 7:43our
- 7:44our initial analysis was done
- 7:47uh on the united states it's obviously
- 7:50not a developing country
- 7:51but you know you can learn a lot from
- 7:53say let me take
- 7:55this particular approach let me
- 7:58do the same exercise in china
- 8:01let me do the same exercise in mexico
- 8:04let me do the same
- 8:06exercise in nigeria and try to
- 8:08understand
- 8:09what are the similarities what are the
- 8:11differences
- 8:12what can we learn from one country
- 8:16for example might it be the case
- 8:19that china is slowly moving
- 8:22into in the direction of
- 8:26the urban system that we have in the u.s
- 8:28and if so
- 8:30what does that imply in terms of
- 8:33future gains or losses in terms of
- 8:38welfare right so there's lots of
- 8:40interesting questions here
- 8:41and so that's going to be the main part
- 8:44of my lecture and then towards the end
- 8:47of the lecture i will want to talk a
- 8:49little bit about a few
- 8:52other papers uh just to give you a
- 8:55flavor
- 8:56of the other work that has been done and
- 8:58that is being done
- 9:00in the area of
- 9:03urban economics and development or even
- 9:06more broadly
- 9:08what we could call spatial economics
- 9:11and development so the difference a bit
- 9:13between urban
- 9:15and spatial would be urban is mostly
- 9:18focusing
- 9:20on uh cities
- 9:23as the word itself says versus
- 9:26a more spatial economics approach a more
- 9:29economic geography approach
- 9:31would would be a little more
- 9:32comprehensive and take
- 9:34take the entire territory or the entire
- 9:38geography of a country including uh
- 9:40including say uh rural areas
- 9:44etc etc okay so without
- 9:48without uh holding you up further let me
- 9:52now turn to the model i will explain
- 9:55this in some detail and then show you
- 9:57some graphs and then move on
- 9:59okay so um so as i told you in the
- 10:02beginning
- 10:03we will be looking at three
- 10:06determinants of what makes
- 10:10a city an attractive place to live
- 10:14right so one determinant could simply be
- 10:17that
- 10:18the location has a high level of
- 10:20productivity
- 10:21so i can move to a city be highly
- 10:24productive
- 10:25earn a decent wage and that makes the
- 10:27city attractive
- 10:29a second reason could be attractive
- 10:32amenities
- 10:33right so people don't only live in
- 10:35cities for productive purposes
- 10:38they also live in cities for
- 10:43consumption purposes in fact it's
- 10:45something that that doug
- 10:46has written about and hopefully we will
- 10:48get to talking a bit about
- 10:50some of his work as well uh and then
- 10:53lastly um
- 10:56some cities are of course better than
- 10:59others
- 11:00in terms of managing
- 11:03what we call frictions but you can think
- 11:05of frictions as
- 11:06urban costs right and this is
- 11:08particularly important
- 11:10in developing countries so we all know
- 11:13that
- 11:13that cities are great places to be
- 11:15productive uh
- 11:17that density is a good thing uh it helps
- 11:20us
- 11:21it helps us be productive but on the
- 11:22other on the other hand
- 11:24it also leads to urban costs right
- 11:27cities
- 11:28tend to be congested cities tend to be
- 11:30polluted
- 11:31et cetera et cetera and some
- 11:34cities are better at managing that than
- 11:38others
- 11:38right um so so so that's those are the
- 11:42three determinants we're going to look
- 11:43at
- 11:44and then the second element of the
- 11:46approach is that
- 11:47we will not look at a single city
- 11:51but instead we will look at the entire
- 11:54system of cities what that means is if i
- 11:57take
- 11:57say the u.s or i take china i'm going to
- 12:00take all the cities in the u.s or
- 12:02take all the cities in china and what's
- 12:04important about that approach
- 12:06is that this is a general equilibrium
- 12:10approach meaning
- 12:11that if um
- 12:15one city is attractive
- 12:19for example that may be because the city
- 12:22itself
- 12:23has some good features but it also may
- 12:25be because other cities are less
- 12:26attractive
- 12:27right so it's a system where people uh
- 12:30can can move across space and so how
- 12:33well i do
- 12:35will obviously depend partly on how well
- 12:39others do and and i think that approach
- 12:41of a system of cities is important
- 12:43because very often when we think about
- 12:45urban policy
- 12:46urban policy is very often run by city
- 12:50governments
- 12:51right and so a city may say i want to do
- 12:53this
- 12:54to make my place more attractive but
- 12:57that doesn't necessarily mean
- 12:59that that is the best thing to do from
- 13:02a systemic uh point of view right and so
- 13:06taking into account uh the entire system
- 13:09of cities i think is
- 13:10is a useful is a useful approach and so
- 13:13once we have this model and once we can
- 13:15quantify
- 13:16we'll obviously be able to run some
- 13:18counterfactual exercises
- 13:20and the counter factual exercises will
- 13:22be a little bit
- 13:23uh along the lines of what i was um
- 13:27talking about in in the introduction i
- 13:30can for example look
- 13:31at would it make sense uh to uh
- 13:35support smaller cities would it make
- 13:37sense
- 13:38to uh try to slow down
- 13:42growth in in bigger cities etc
- 13:45right and then as i said we will compare
- 13:47the us
- 13:48and china okay so the model
- 13:52we have a system of i
- 13:55cities each city will be characterized
- 13:58by a level of productivity
- 14:00by a level of amenities and then a level
- 14:03of what we call
- 14:04excessive frictions which reflect this
- 14:06efficiency of providing
- 14:08uh urban infrastructure that deals with
- 14:11that deals with congestion i'll have to
- 14:13be a little bit more specific about
- 14:15that third point in a in a second
- 14:18okay and then we'll have uh n
- 14:21agents or individuals or households and
- 14:24they can choose where they live and work
- 14:27and so the urban equilibrium will be one
- 14:30where
- 14:31utility uh equalizes across
- 14:35space so in terms of technology
- 14:39so we have goods that are being produced
- 14:42in these different cities
- 14:44as i said uh a city i will have a
- 14:46particular productivity
- 14:48ait and then production will depend on
- 14:52that productivity
- 14:53it will depend on capital and it will
- 14:55depend
- 14:56on on hours worked right
- 15:00capital will be freely mobile across pay
- 15:02so there will be a
- 15:03common a common interest rate in terms
- 15:06of
- 15:07preferences we will say that preferences
- 15:10depend
- 15:11on your consumption right it will also
- 15:14depend
- 15:16on your leisure right so i have one
- 15:18minus h
- 15:20where h is the hours you work the more
- 15:22you work
- 15:23the less utility you have so i have
- 15:25consumption i have leisure
- 15:27and then i have this gamma term in here
- 15:30gamma i
- 15:31i is a subscript for a particular city
- 15:34which will denote
- 15:35the city's amenities right and so we'll
- 15:38take that as a as a
- 15:40fixed characteristic in the exercise
- 15:43we're doing
- 15:44that just could be that you know if your
- 15:46city
- 15:47is one of the students i can see you
- 15:49have the golden gate bridge behind you
- 15:51if your city is located in the san
- 15:54francisco bay area
- 15:55well that's just a nice location that
- 15:58will add to the amenities
- 16:00of of that place right so so then
- 16:03the agent will obviously maximize
- 16:05utility subject to
- 16:07it to a budget constraint and without
- 16:09going into too much too many details
- 16:11here
- 16:12i just want to flag one thing in a
- 16:14budget constraint here
- 16:15or a few things one is that um
- 16:19that there will be a tax rate
- 16:22tau right which is levied on
- 16:26people's wages and that tax rate tau
- 16:30is actually what's going to finance
- 16:33the urban infrastructure right so people
- 16:36are going to be living
- 16:37in in this city they will need to be
- 16:39able to commute to work
- 16:41and the city will have to provide urban
- 16:42infrastructure
- 16:44call it roads or commuting
- 16:45infrastructure and that will cost
- 16:47something and that's what we're going to
- 16:49be calling it
- 16:51that's going to be financed by this tax
- 16:53style
- 16:55r will be referring to the fact that
- 16:58people live on on land and they need to
- 17:00pay rent
- 17:02and then t will refer to commuting but i
- 17:05will get
- 17:05i will get to that in in a second um
- 17:09okay so you can you can solve this uh
- 17:12this
- 17:12utility maximization problem and you get
- 17:15this first order condition
- 17:17right which obviously will depend uh on
- 17:20this
- 17:21tax tau and so the stack style will
- 17:25distort
- 17:26obviously your your your optimal
- 17:30decision
- 17:30of how much you want to how much you
- 17:33want to
- 17:34work right because it's a tax on labor
- 17:38and so sometimes in the literature
- 17:40rather than calling this
- 17:41tau a tax some people prefer to refer to
- 17:45tao
- 17:46as a labor wedge uh what's the
- 17:49difference between the two
- 17:51the the difference between the two is
- 17:53tao as a tax is obviously
- 17:55a very concrete concept you say okay
- 17:58there's a tax rate of say
- 18:00seven and a half percent and that's what
- 18:02i'm gonna call tao
- 18:03versus saying no no no tau is anything
- 18:07that kind of distorts my decision of
- 18:10how much how many hours i want to work
- 18:13and that could partly be
- 18:14taxes but it could partly be other
- 18:19maybe frictions or regulations or
- 18:23things that have to do with the context
- 18:26in which i live
- 18:27which which distort my decisions and so
- 18:30if you take that broader view then we
- 18:33would refer to tao as a labor wedge
- 18:35right and so what you have to understand
- 18:37is that when we call it the labor wage
- 18:39it's partly referring to taxes but it
- 18:41could partly be referring to other
- 18:43things
- 18:44and it's a bit of a black black box kind
- 18:47of approach
- 18:48where where we don't really want to be
- 18:51too specific of
- 18:52what other things might be in that towel
- 18:55right
- 18:56and so anyway that's just a bit of a of
- 18:59a side note here
- 19:00and then as i said agents will be
- 19:04freely mobile across cities and so
- 19:08utility will equalize across space
- 19:11okay uh so uh right
- 19:15for now i haven't really said anything
- 19:18yet about
- 19:19uh what it means to be a city the only
- 19:22thing i've said is there's these
- 19:23different
- 19:24points in space that have different
- 19:26productivity levels
- 19:27different amenity levels and different
- 19:29taxes and then people will allocate
- 19:31themselves
- 19:32across space until utility equalizes
- 19:35across all these points but what exactly
- 19:38does it mean
- 19:39here to be a city and can we give some
- 19:41more structure to what it means to be a
- 19:43city
- 19:44right and so a very standard model
- 19:47that is used in urban economics
- 19:50is called the monocentric city model
- 19:54and so the monocentric city model uh
- 19:57what it tries to
- 20:00what it tries to kind of conceptualize
- 20:02is the idea
- 20:04that uh cities are not only productive
- 20:08places but cities also
- 20:10cause some kind of congestion because
- 20:13people need to live
- 20:14somewhere and then they need to get to
- 20:16work right and the monocentric model
- 20:19the assumptions it makes is that
- 20:22production
- 20:23happens at the city center right call
- 20:26that sort of the central business
- 20:27district
- 20:28and then people live in concentric
- 20:32circles around that city center
- 20:36of course at different distances right
- 20:38they go away from the center
- 20:40we will assume that every individual
- 20:44occupies one unit of land and so as
- 20:48more people move to the city the city
- 20:51will grow
- 20:52and the distance from the furthest away
- 20:55resident to the city center
- 20:56will of course also grow and so then you
- 20:59face a trade-off
- 21:00right the people who are going to be
- 21:02living further away
- 21:04will have to commute longer distances
- 21:08right commuting is costly you can model
- 21:10this in different ways you can think of
- 21:12commuting being costly in terms of time
- 21:15we we modeled it here in this particular
- 21:18paper
- 21:19as commuting being costly in terms of
- 21:21goods
- 21:23and so the commuting cost td
- 21:26d being the distance from where you live
- 21:28to the city center
- 21:29will be kappa d right so some kind of
- 21:33a parameter times times the distance
- 21:36now as i said people live on on everyone
- 21:39lives on one unit of land
- 21:40and pays a particular rent rd
- 21:44which also changes with distance and we
- 21:46will normalize
- 21:48the price at the price of land
- 21:51at the city border sort of at the fringe
- 21:54of the city
- 21:55we will set that equal to zero you can
- 21:57set it equal to a
- 21:58concept it doesn't matter but we'll set
- 22:00that equal to zero
- 22:01so r d d bar where d bar is the
- 22:05the city border let's say right the fir
- 22:08the point furthest away from the city
- 22:10center
- 22:10we'll say that the rents over there are
- 22:12equal to zero and then we will
- 22:14make the assumption that all agents in a
- 22:17city
- 22:18can choose where they live if everybody
- 22:21can choose where they live
- 22:23then the sum of the rents that you pay
- 22:27plus the commuting costs that you pay
- 22:32that must equalize across people right
- 22:34and what that
- 22:35implies is that the person living
- 22:39furthers away from the city center
- 22:41will pay the highest commuting cost
- 22:43actually kappa d bar
- 22:45but will pay zero rents and then the
- 22:47person living closest to the city center
- 22:50will actually be paying essentially zero
- 22:53commuting costs right
- 22:54but will pay the highest rents and so
- 22:56you have a
- 22:57what they call a rent gradient and
- 23:00that's a very typical thing that we see
- 23:02in urban economics it's something which
- 23:04is very well studied the idea that
- 23:06rents tend to decrease
- 23:10with distance from the city center
- 23:14because it is compensating people
- 23:18for for longer commutes anyway and so
- 23:21we have the setup and so then you can of
- 23:23course if you say everybody lives
- 23:26on one unit of land if i have a
- 23:28particular population
- 23:29nit in the city right
- 23:32i can calculate how big the city should
- 23:35be i can calculate the radius of the
- 23:37city d
- 23:37bar once i know how many people live in
- 23:41the city and how big the city is
- 23:43i can actually also calculate the total
- 23:46miles traveled
- 23:47right how how what is the total amount
- 23:49of commuting
- 23:50that is being done in the city and
- 23:53what's interesting about that as you can
- 23:55see in this
- 23:55this expression here is that this is
- 23:58actually convex in in
- 24:02the number of people who live in the
- 24:04city and that gives you a little bit
- 24:06this idea that yes
- 24:07as cities grow maybe the productivity
- 24:10may go up
- 24:11but there's also you know congestion
- 24:13costs or these costs of of size
- 24:16are also increasing in in in in a convex
- 24:19way
- 24:20and that is actually important for the
- 24:22following reason
- 24:23if if if congestion wouldn't be um
- 24:27increasing in a convex way at the end
- 24:32everybody would want to live in the same
- 24:34city right which would be say the most
- 24:36productive city or the
- 24:37the city with the best productivity
- 24:39slash the best amenities
- 24:41right and so we of course know that in
- 24:44reality
- 24:45not everybody lives in the same city
- 24:47there's many cities across
- 24:49the territory and one one important
- 24:51reason for that of course is that
- 24:54there's a limit to how big a city can be
- 24:57right and so if you think of a city
- 24:59stretching a hundred miles for example
- 25:02but at some point the city becomes too
- 25:04big
- 25:05and it becomes too costly congestion
- 25:08becomes too costly to
- 25:09deal with and and so new cities would be
- 25:12formed
- 25:13okay um so that's kind of the setup
- 25:17then uh lastly uh
- 25:21so so we have the city we have this need
- 25:24to commute
- 25:25uh the government city government in
- 25:28this case
- 25:28will have to provide urban
- 25:31infrastructure
- 25:32transport infrastructure uh to uh
- 25:35to to have these people to have its
- 25:37residents
- 25:38uh commute and what we will assume is
- 25:41that
- 25:42the the cost of providing this transport
- 25:45infrastructure
- 25:46will depend on the total commuting cost
- 25:49which is this this expression here that
- 25:51you see at the end
- 25:52times the kappa and it will also depend
- 25:55on
- 25:56wages right of a worker
- 25:59or workers wage is actually w times h
- 26:02but then it will also depend
- 26:04on this uh this variable which we call
- 26:08git and this is what we will call the
- 26:11inefficiency or the frictions or these
- 26:13excessive frictions
- 26:14of of different city governments and so
- 26:17to be
- 26:18to be to be very clear what we kind of
- 26:21mean by g is the following
- 26:25g is not referring to the fact that
- 26:28bigger cities
- 26:29become more congested it's it's more the
- 26:32idea that
- 26:33if i take two cities of equal size
- 26:37right that are equally congested right
- 26:41in terms of how much commuting happens
- 26:43etc
- 26:44some city governments are better
- 26:47are more efficient at
- 26:51dealing with this than others they're
- 26:53they're more efficient at providing this
- 26:55infrastructure than others
- 26:56the one that's more efficient would have
- 26:59a higher g
- 27:00sorry would have a lower a lower g the
- 27:02one that's less efficient
- 27:04would have a higher g right and so
- 27:06that's why we in the paper we refer to
- 27:08this as excessive frictions
- 27:10because typically yes as cities grow
- 27:12frictions increase
- 27:14but but given those that increase in
- 27:17frictions
- 27:18some are bet some some city governments
- 27:20are better and some are worse
- 27:21at actually providing those those uh
- 27:25that infrastructure they're better or
- 27:26worse in terms of
- 27:28dealing with uh with those frictions
- 27:31okay so
- 27:32so that's kind of the idea and
- 27:36and and of course all these costs of
- 27:38providing transport infrastructure is
- 27:41then what will be
- 27:45financed by that labor
- 27:48tax towel okay um
- 27:51all right well um then of course
- 27:54characterization of equilibrium is
- 27:55actually very simple
- 27:56as i said you know people just allocate
- 27:59themselves across space
- 28:00until you tilt the equalizers and so
- 28:03what we really only need
- 28:04so so just to to sort of simplify a bit
- 28:08the only uh the only things i kind of
- 28:11need to know
- 28:13to solve this model is if i have
- 28:15information on
- 28:17productivity and on amenities
- 28:21right i have information on a i have
- 28:24information on gamma
- 28:25and i have information on this
- 28:28efficiency or these frictions with which
- 28:31governments supply infrastructure just
- 28:35git
- 28:36if i have a triplet if i have this
- 28:38triplet
- 28:39for all cities i then
- 28:43i can actually solve the model right i
- 28:45can me when
- 28:46by solving the model what i mean is i
- 28:49can tell you
- 28:50how many people will live in every
- 28:52single place
- 28:53right which is the main thing we're
- 28:55looking at because once i know that
- 28:57i can of course start looking at what
- 28:59does that mean in terms of
- 29:01city size distribution what does that
- 29:02mean in terms of
- 29:04welfare etc etc okay and of course
- 29:08as you can imagine the in in equilibrium
- 29:11we will find that more productive cities
- 29:13will be larger
- 29:15we will find that cities with better
- 29:18larger
- 29:18amenities are also larger and then we
- 29:21will find that cities with these
- 29:23higher excessive frictions higher git
- 29:26will be smaller right and so what we
- 29:30will do now
- 29:31is i will show you very briefly how we
- 29:34get
- 29:34data on these on on this triplet
- 29:39for all metropolitan areas in the u.s
- 29:42and then i can show you
- 29:43what we do in terms of exercise uh
- 29:47and then i will show you what we do
- 29:50for china and the comparison between
- 29:54the two will actually be i hope uh quite
- 29:57uh
- 29:57quite interesting okay uh
- 30:01are there any questions on
- 30:05the model part
- 30:11i was wondering a bit um how realistic
- 30:14it is to have these taxes be um
- 30:18being like on a city level
- 30:22yeah so so so uh you're actually quite
- 30:25right some of the more
- 30:27simple urban models would just say look
- 30:30let us just consider productivity and
- 30:33amenities as a two main characteristics
- 30:36that make cities different
- 30:39and that's kind of enough to understand
- 30:43most of the insights we can get from
- 30:46urban economics
- 30:48here as i said and and that's why
- 30:52you know that that's why your your
- 30:55question
- 30:56is useful um
- 30:59you can think of it as being a tax
- 31:02and then you can of course ask yourself
- 31:04yes well how how might how which part of
- 31:06these taxes are actually
- 31:07local taxes which part are state taxed
- 31:10which part of federal taxes
- 31:11it's obvious that part of the urban
- 31:14infrastructure
- 31:15will actually be let's say city roads
- 31:18right
- 31:18they typically are financed by
- 31:21property taxes which are local taxes
- 31:24right and so from that point of view we
- 31:26think
- 31:27our assumption is actually quite
- 31:29reasonable a lot of the
- 31:31local commuting infrastructure is
- 31:34actually financed
- 31:35by by local taxes uh
- 31:38but but again it's a bit of a broader
- 31:40concept
- 31:42uh you can go beyond the idea of
- 31:45of of strictly thinking of of it as
- 31:47being a tax
- 31:48and go to this idea of a labor wedge
- 31:52which would which would simply be
- 31:54telling you that
- 31:56some cities seem to be more efficient
- 31:59in terms of dealing with say
- 32:02congestion or dealing with urban
- 32:04infrastructure than others
- 32:06right um yeah so so those are the two
- 32:10parts of the
- 32:10of the answer but when we when we sort
- 32:13of
- 32:14get estimates of the style and when i i
- 32:18actually correlated those estimates of
- 32:20tao that are sort of predicted by the
- 32:21model
- 32:22and and i compared it to uh local taxes
- 32:26the correlation is actually quite high
- 32:28so so
- 32:29so it correlates well our notion of tau
- 32:33in the model actually correlates quite
- 32:35well with
- 32:37with the local taxes so that's that's
- 32:40what i can say about that for now
- 32:42um anything else any other quick
- 32:45question
- 32:45klaus i have a clarifying question for
- 32:47you in the
- 32:49q a from veronica goyal linking this
- 32:51back to the misallocation lectures that
- 32:53people have had
- 32:54yes if people relocate to a city because
- 32:57of
- 32:57amenities not productivity
- 33:00can that lead to misallocation in the
- 33:03aggregate
- 33:04how do you think about what's uh what's
- 33:06interesting of course is that
- 33:10when you have only one characteristic so
- 33:12suppose we say the only thing we have
- 33:15here
- 33:15is productivity then then
- 33:19then all these predictions are
- 33:20relatively straightforward right you
- 33:22want people to go to places
- 33:24that are more productive and leave
- 33:26places that are less productive and
- 33:27you're done
- 33:28over here it's a bit more complicated
- 33:31because
- 33:33not only do we have three determinants
- 33:36but
- 33:36the question is what are the
- 33:38correlations between them
- 33:40right is it typically the case that
- 33:42higher productive cities
- 33:43are also higher amenity cities that may
- 33:46be the case yes or maybe no
- 33:48and so uh
- 33:53so so so what what we can say is that
- 33:56if people move to cities with higher
- 33:59amenities
- 34:00that will of course be that that will
- 34:03improve
- 34:03their utility right and so it will
- 34:07improve welfare but but it may actually
- 34:10decrease
- 34:10uh it may decrease efficiency if it
- 34:14turns out that the higher amenity
- 34:16cities are cities with lower with lower
- 34:19efficiency
- 34:20right and so if you take if you take a
- 34:23view of
- 34:24misallocation as only referring to
- 34:27misallocation from the efficiency point
- 34:29of view
- 34:30versus if you take a view of
- 34:32misallocation
- 34:34from a welfare point of view right and
- 34:35so we're talking here about
- 34:37welfare and so yes it is possible that
- 34:41as you are maximizing welfare by letting
- 34:44people move
- 34:45where they want and they might be going
- 34:47to places with better amenities
- 34:49that that efficiency actually goes down
- 34:52that's possible
- 34:55okay sorry i also have a question about
- 34:58the
- 34:59labor tax yes
- 35:02i'm not sure whether i understand it
- 35:04right but uh
- 35:06in the production function it seems that
- 35:08the
- 35:09liberal text doesn't distort the
- 35:12production i think so the which is what
- 35:15it does is it it
- 35:16it affects uh if you go back here it
- 35:19affects
- 35:20the choice of the hours worked
- 35:24right and so you can kind of see this
- 35:26here from
- 35:27the tao entering into your into your
- 35:30budget constraints so so the tau will
- 35:33depend on the hours you work so it's not
- 35:35it's not a sort of it's not a tax that's
- 35:38fixed
- 35:38per person it's a tax that depends on
- 35:41how many hours you work
- 35:43and so when you think about the
- 35:45equalizing marginal
- 35:48marginal benefit and marginal cost
- 35:51higher labor taxes will
- 35:54push you towards working uh less
- 35:58hours which is something you can see in
- 36:00this first sort of condition here
- 36:02right and so so in that sense it is a
- 36:05it's a sort of a standard distortionary
- 36:09labor tax okay
- 36:14okay one more question um
- 36:18how about the
- 36:21the the key assumption is that the the
- 36:23cities are homogeneous right
- 36:29in what sense i mean are we looking at
- 36:31the structure
- 36:33and the factors that uh
- 36:36determine uh these
- 36:39cities are common to all is that is that
- 36:42is it clear to say yeah so so well so so
- 36:46uh so of course each city
- 36:49has a different so here as you can see
- 36:51this ait the gamma i t and the git are
- 36:54really the
- 36:55the three fundamental drivers and so the
- 36:58only thing is that the i
- 37:00so so the structure is the same yeah so
- 37:02the the model is of course the same
- 37:04model and what makes one city
- 37:06attractive or another it's the same
- 37:08types of determinants
- 37:09but but they do have an eye subscript
- 37:12meaning
- 37:13these are three characteristics which
- 37:16are
- 37:16city specific so different cities will
- 37:18obviously have different levels of these
- 37:20three
- 37:21of these three determinants but
- 37:23otherwise yes the structure
- 37:25the structure is the same for all the
- 37:27cities okay how do we account for
- 37:30endowment and maybe some cities are
- 37:33endowed with certain
- 37:34uh maybe resources um yeah so so that
- 37:38would actually in
- 37:39that would show up in our in a higher
- 37:42ait
- 37:43okay right so a city that is for example
- 37:46either well endowed with some natural
- 37:48resources or maybe
- 37:50uh located in a port in in a place
- 37:53that's
- 37:54that's easily accessible that that that
- 37:57would that would show up in the ait
- 37:59okay thank you okay all right
- 38:02and so then what do we do we have data
- 38:04on all these metropolitan areas in the
- 38:06u.s
- 38:07uh production we measure by gdp
- 38:11consumption we don't really have data on
- 38:14consumption by
- 38:16by msa by metropolitan area and so we
- 38:19actually use uh
- 38:20retail earnings and then adjust for
- 38:23national averages
- 38:25to get to get
- 38:28a measure of consumption at the city
- 38:30level and we add to that
- 38:33housing housing consumption
- 38:36capital we take actually u.s sector
- 38:39capital stocks
- 38:40and allocated to msas according to
- 38:44their shares and in sector learnings and
- 38:46then for hours work we use
- 38:48the current population survey um so how
- 38:51do we get ait
- 38:53ait we just get from this expression
- 38:56here so we have a measure for y
- 38:58for k and for h so we get ait that way
- 39:02the labor wedge of course we need some
- 39:05assumptions on what
- 39:06size and theta etc but we have a measure
- 39:09of
- 39:10of c of h and of a so we can back out
- 39:14tau then the excessive frictions git we
- 39:18actually take the govern
- 39:19government budget constraint uh we take
- 39:22logs
- 39:23and then we run this regression here and
- 39:26the residual is actually
- 39:28what we call uh uh is the log of git so
- 39:31we can back out git this way
- 39:33and then the manatee levels we it is
- 39:36kind of a residual
- 39:38right so we we use the model
- 39:42and then
- 39:45determine the amenity levels gamma i t
- 39:50so that the model generated
- 39:53distribution of people across cities
- 39:55actually matches
- 39:57the one that we see in the data
- 40:00okay all right so let me
- 40:04and then we also have a way of getting
- 40:07getting an estimate of kappa right kappa
- 40:10is if you remember that's the cost of
- 40:13the cost of commuting per per mile or
- 40:16per kilometer
- 40:18traveled okay so so with all of this
- 40:21we can you know once we have the as i
- 40:22said once you have these triplets for
- 40:24all the msas
- 40:26and you have parameter values you can
- 40:28just uh
- 40:29allocate people across cities and and
- 40:31then you can start doing some exercises
- 40:33okay that's that's the nature of what
- 40:36we're doing here uh
- 40:38here's one graph just sort of
- 40:40introductory
- 40:41uh to because you'll see a lot of these
- 40:43types of graphs
- 40:44so these types of graphs you may have
- 40:47seen in other
- 40:48lectures or in in your career in
- 40:51economics
- 40:52this type of graph to represent size
- 40:55distributions
- 40:56you know farm size distribution or
- 40:58whatever here it's the
- 41:00city size distribution and so what we
- 41:02have on the
- 41:04x-axis the horizontal axis is the
- 41:08log of population and what i have on my
- 41:10y-axis
- 41:12is the log of the probability
- 41:16of being bigger than the population on
- 41:18the on the on the x-axis
- 41:20so that's a little bit of a of a
- 41:22mouthful
- 41:23uh but but the way to maybe easier for
- 41:26me to say is
- 41:27the way to interpret these these graphs
- 41:30are
- 41:30if the graphs are flatter right
- 41:34say the red one or the orange one
- 41:36[Music]
- 41:37then you have more dispersion
- 41:40in the city size distribution you know
- 41:43on the top
- 41:44the top kind of the smaller cities right
- 41:46so i have more small
- 41:47cities and i have more large cities
- 41:51right so it's a little more dispersed if
- 41:54if it's a little steeper right then
- 41:57there's less dispersion meaning
- 42:01uh the city sizes are of more
- 42:04equal equal size and so
- 42:10excuse me just as a as an example here
- 42:13for instance if you compare
- 42:16the red the red
- 42:21the red curve to the blue one
- 42:25the red one is for a lower level of
- 42:28commuting cost
- 42:29than the blue one so think about what
- 42:31that means
- 42:32intuitively if if i increase commuting
- 42:36costs
- 42:37who is that going to be bad for well
- 42:39that's typically going to be bad
- 42:41for cities where there's a lot of
- 42:42commuting right so that will be
- 42:45bad let's say for the bigger cities
- 42:47right and so
- 42:48higher kappa would tend to make
- 42:52the bigger cities smaller and the
- 42:54smaller cities bigger
- 42:56right that explains why the blue or the
- 42:59light blue curve
- 43:00is kind of steeper than
- 43:04the red one so the red one is for lower
- 43:07commuting costs
- 43:09it's not as costly to be big so i see a
- 43:11more dispersed city sizes
- 43:13distribution for higher commuting cost
- 43:16i see a less dispersed city size
- 43:20distribution
- 43:21okay and of course then you can look at
- 43:25utility and welfare etc but let me move
- 43:27on
- 43:28in the in the interest of time here so
- 43:30so here's the first
- 43:32exercise where what we do
- 43:35is the following we say
- 43:39what would happen to the city size
- 43:43distribution
- 43:45if for example we eliminated
- 43:50all productivity differences across
- 43:52space
- 43:53right or what would happen to the city
- 43:56size distribution
- 43:58if we eliminated all amenity differences
- 44:01across space
- 44:03and so just just to explain a little bit
- 44:05better
- 44:06the blue curve in all four pictures
- 44:10is the actual city size distribution
- 44:13right the ones that are colored in
- 44:16in another color not blue are counter
- 44:19factual city size distributions
- 44:21so let me for example uh
- 44:24call your attention to the one on the
- 44:26top right
- 44:28so the green curve is
- 44:31the city size distribution that i would
- 44:34get
- 44:35if all cities had the same
- 44:39efficiency level in the u.s right
- 44:42the purple one here at the bottom left
- 44:45is
- 44:45what would the city size distribution
- 44:47look like if all cities had the same
- 44:49amenity levels and and the black one is
- 44:53what would the city size distribution
- 44:54look like if all
- 44:56cities had the same level
- 44:59of of excessive friction so what you see
- 45:03is a couple of things for example if you
- 45:05look at efficiency
- 45:07yeah you know the city sizes region
- 45:08doesn't look that different
- 45:10there's a little bit uh
- 45:14you know there's maybe a little bit this
- 45:16is some more smaller cities
- 45:19but on the top part of the distribution
- 45:21you don't really see a very big
- 45:22difference
- 45:23in terms of utility equalizing
- 45:27efficiency of cross space
- 45:29now you know the utility goes from 10 to
- 45:3210.12 so
- 45:33there's a little bit of a improvement in
- 45:36utility but again it's not a whole lot
- 45:38right so the the welfare effects is
- 45:42a kind of an increase by 1.2 percent so
- 45:44the welfare effects of equalizing
- 45:47efficiency across space in america is
- 45:49actually not that big
- 45:51although you do get a lot of
- 45:53reallocation
- 45:54so the reallocation here is measured by
- 45:58uh the the increase in the population
- 46:01and the cities that are growing
- 46:03divided by the total population so you
- 46:06do get a lot of reallocation
- 46:08a lot of people moving across space but
- 46:10the city size distribution is not
- 46:12changing very much
- 46:13and overall utility is not changing very
- 46:16much either
- 46:17and so you look at these utility numbers
- 46:19here and that's true for efficiency
- 46:22it's true for equalizing amenities
- 46:25across space it's true for equalizing uh
- 46:29[Music]
- 46:30excessive frictions across space but but
- 46:32in all three cases the reallocation is
- 46:35relatively big
- 46:36welfare effects are relatively small
- 46:38city size distribution doesn't change
- 46:40very much maybe except in this
- 46:42particular case
- 46:43where you get a much less dispersed
- 46:47city size distribution so that's an
- 46:49interesting
- 46:50first observation right
- 46:53you can of course do many things with
- 46:56this
- 46:58rather than looking at the the the
- 47:01entire distribution
- 47:02you could say let me look at
- 47:05certain particular cities what happens
- 47:08to them
- 47:09right so for instance let me look at
- 47:12efficiency here
- 47:13if you equalize efficiency across space
- 47:17look at the city size distribution you
- 47:19don't see that much happening
- 47:20but but when you look at the data for
- 47:22individual cities
- 47:24the effects are actually quite big yeah
- 47:26well not surprising the most efficient
- 47:28cities will obviously lose
- 47:30that's what happens when you equalize
- 47:32efficiency across space of course others
- 47:34that are less efficient will gain
- 47:36right and so uh at the individual city
- 47:39level
- 47:40you see big changes that's of course
- 47:42what then explains
- 47:44the big reallocation across space you
- 47:47know there wouldn't be bigger
- 47:48reallocation across space
- 47:50if if there's no big effects at the
- 47:53local level
- 47:54right uh the same is true with amenities
- 47:57so if you equalize amenities across
- 47:59space
- 48:00the east coast what gained
- 48:03what does that mean well that means that
- 48:05these places don't have very good
- 48:06amenities
- 48:07right because if they get the average
- 48:09amenity they'll do better
- 48:11the west coast loses but that would
- 48:14tell you that they actually have good
- 48:15amenities if you give them the
- 48:17average amenities they will end up doing
- 48:19worse
- 48:22right so so there's lots of interesting
- 48:24if you're interested in particular
- 48:26cities
- 48:26there's lots of interesting insights uh
- 48:30and there's lots as i said lots of
- 48:31reallocation but not a whole lot of
- 48:34welfare gains and you can look at this
- 48:37in maps
- 48:38for example one interesting thing is
- 48:40that if you eliminate
- 48:42or if you make all these frictions equal
- 48:45across
- 48:46cities the places that are gonna gain
- 48:49are the brown
- 48:50the brown areas so you see a lot of the
- 48:52cities actually in the rust belt
- 48:54uh would be gaining a population
- 48:58if they had the same level of frictions
- 49:00of the rest of the country i thought
- 49:02that was kind of an interesting
- 49:04and interesting finding so lots of lots
- 49:07of
- 49:07cool stuff you can do with this um
- 49:11but let me let me know for the for the
- 49:15remaining 10 minutes before i sort of
- 49:17switch to the second part of the lecture
- 49:19let me actually uh talk a bit about
- 49:23uh china okay um
- 49:26so so we've seen this exercise for the
- 49:29u.s
- 49:30let's do the same exercise for china
- 49:32right
- 49:34well a couple of interesting
- 49:37differences let me focus on the one of
- 49:41productivity then i'll talk a bit about
- 49:43amenities as well but
- 49:44let's look at the top right graph over
- 49:48here
- 49:48so once again the blue curve
- 49:52is the actual observed
- 49:55city size distribution the green one
- 49:58here
- 49:59is how would the city size distribution
- 50:02look like
- 50:03in china if everyone had the same
- 50:07level of productivity okay so the first
- 50:11thing you notice
- 50:12is that
- 50:15uh as you can see this curve has become
- 50:17flatter right
- 50:18flatter remember means more dispersion
- 50:21the bigger cities are actually becoming
- 50:23bigger the smaller cities are becoming
- 50:25smaller
- 50:26right that's interesting uh
- 50:30because you know we've talked a bit
- 50:31about uh mega cities
- 50:34are mega cities desirable are they not
- 50:36desirable etc
- 50:38here we're kind of finding hey you know
- 50:40if everybody had the same efficiency
- 50:41level
- 50:42uh we would see even bigger cities than
- 50:45the ones we see today
- 50:47in china and the cities are as you know
- 50:48already very big in china
- 50:50right and so if anything we'll see
- 50:54more big cities and bigger big cities in
- 50:56china
- 50:57if there is a efficiency efficiency
- 51:00equalizes across space
- 51:01the other very interesting thing here is
- 51:04remember in the case of the us
- 51:06we had a welfare increase of 1.2 percent
- 51:12uh when you equalize efficiency across
- 51:14base here you have a wealthier increase
- 51:16of 46 percent right or 47 percent
- 51:21uh log point but let's let's just call
- 51:24it 47 percent here
- 51:26huge difference huge welfare gains
- 51:29from equalizing efficiency across space
- 51:31so so that of course
- 51:32ties in i think probably with
- 51:36some of the discussions you've had on
- 51:38misallocation
- 51:40in your in your other lectures and so
- 51:43what is very interesting to me about
- 51:45this is
- 51:47you know at some level it shouldn't
- 51:49maybe surprise you
- 51:51right and the reason why maybe this
- 51:52shouldn't surprise you
- 51:54is well as with many other
- 51:58emerging economies
- 52:01you know the difference in efficiency or
- 52:04in productivity across space
- 52:06in china is way way way way bigger
- 52:09than the difference in efficiency across
- 52:12space in the us
- 52:14right in mature economies yes of course
- 52:16there's more efficient
- 52:17places and less efficient places in the
- 52:19u.s but
- 52:20the differences are not that big in
- 52:22china these differences are an order of
- 52:24magnitude bigger they're
- 52:26large right you take the you take the
- 52:28most advanced
- 52:30cities on on the eastern seaboard in
- 52:34china
- 52:34well these cities are very similar to
- 52:38cities in very advanced economies you go
- 52:40all the way
- 52:41to western china and you will find
- 52:44cities that are still very far behind in
- 52:47terms of in terms of development
- 52:49and so that's interesting to observe and
- 52:52so in that sense yes obviously there's a
- 52:54lot of misallocation
- 52:55it's not real misallocation because the
- 52:57efficiency is whatever it is
- 52:59but but there's misallocation in the
- 53:01sense that you know
- 53:02the efficiency hasn't spread to all
- 53:04these places yet if it would
- 53:07then then you would see these big you
- 53:09would see this big
- 53:11you would see this big welfare welfare
- 53:15gains
- 53:16the other thing that's interesting about
- 53:17this counterfactual exercise
- 53:19is that of course if you say let me uh
- 53:23sort of fast forward a couple of decades
- 53:26right maybe 20 30 40 years
- 53:29we kind of know where china is heading
- 53:32obviously
- 53:33because of technology diffusion across
- 53:36space
- 53:37it's very clear that these very
- 53:40large efficiency differences across
- 53:43cities in china
- 53:44will become smaller right that's the
- 53:46standard thing that happens
- 53:49with space and development development
- 53:52typically in the early stages is very
- 53:54uneven across
- 53:55space but then eventually the efficiency
- 53:58diffuses across space
- 54:00making efficiency more equal right and
- 54:03so
- 54:04we we if we had i mean of course we
- 54:07don't know but if you had to make a
- 54:08prediction
- 54:09it's very likely that the spatial
- 54:11differences in efficiency will become
- 54:13smaller
- 54:13and if that's true then it's very likely
- 54:17that we'll see something like this
- 54:18happening in china
- 54:20and that the potential welfare gains
- 54:23from that
- 54:24are actually pretty large and what's
- 54:26interesting about this exercise is that
- 54:28when we say we're making efficiency
- 54:30equal across space
- 54:31it's not that we're giving everybody the
- 54:34best efficiency in the country
- 54:35we're just equalizing it to the average
- 54:38right so we're not
- 54:39increasing we're not increasing
- 54:42average efficiency right the population
- 54:44weighted efficiency is the same
- 54:47as as as as the one in the data
- 54:50right we're just allowing it to be more
- 54:53equally spread across across
- 54:57the geography right and so we we thought
- 55:00that was very interesting because it
- 55:01it's really very very different from
- 55:04what we saw
- 55:06in in the case of the us and again big
- 55:08reallocation et cetera et cetera
- 55:11okay so uh
- 55:14a few more things uh before
- 55:17i finish with this uh part
- 55:21of of the lecture um
- 55:25is is the following i just want to give
- 55:27you a flavor of
- 55:28what other types of exercises could you
- 55:31do
- 55:32with with this uh with this framework
- 55:35so uh one thing we did is
- 55:39we looked at uh
- 55:42a policy or we compared a
- 55:46policy that would target uh
- 55:50lagging cities meaning cities that are
- 55:53behind
- 55:53in terms of either efficiency amenities
- 55:55or frictions
- 55:56versus a policy that would target
- 56:00either medium-sized or small cities
- 56:04and and try to look at what would give
- 56:07us
- 56:08uh the greater or the bigger welfare
- 56:11effects
- 56:11and the reason why we wanted to look at
- 56:13that is because
- 56:16china for a while at least
- 56:19had this policy which i mentioned here
- 56:21at the top in in
- 56:22italics of controlling the big cities
- 56:26moderating the development of
- 56:28medium-sized cities
- 56:29and encouraging the growth of small
- 56:31cities so you can say okay
- 56:32what would happen if we actually gave
- 56:35incentives for small cities to grow
- 56:38would that be a good thing
- 56:40so so here's what you see for instance
- 56:42if you look at
- 56:44the first row of the table this would be
- 56:48what happens if i take the worst cities
- 56:52in terms of either efficiency amenities
- 56:54or frictions and i improve
- 56:56let's say their efficiency by 20
- 56:59okay or i improve their amenities by 20
- 57:03what are the welfare effects in the
- 57:05aggregate
- 57:07right to get a 5 welfare increase you're
- 57:09getting 11 welfare increase
- 57:11in amenities versus if you target the
- 57:14same type of policy
- 57:16but you look at the smallest cities so
- 57:18you you
- 57:19increase the smallest city improve small
- 57:21cities by 20
- 57:23you typically get smaller effects
- 57:27so anyway what this means is you could
- 57:30use
- 57:31a framework like this to uh to look at
- 57:34different policies
- 57:36right it doesn't make sense to target
- 57:38the smaller cities
- 57:39right or or or again does it make sense
- 57:43to try to slow down
- 57:45growth in big cities is that is that a
- 57:47reasonable policy
- 57:48from from the welfare point of view um
- 57:51[Music]
- 57:53so so that's that's kind of the
- 57:55framework here we actually in
- 57:57in a in in another paper also compared
- 58:01uh this exercise or we implemented this
- 58:04exercise for
- 58:06from mexico and in mexico
- 58:09you find something which is somehow
- 58:11somewhere in between
- 58:12china and the us but actually much more
- 58:15close
- 58:16to the us than to china right so we
- 58:18don't find
- 58:19a particularly high welfare effects in
- 58:22mexico either they're a little bit
- 58:23bigger than in the us and so
- 58:25yes it's somewhat in between but but
- 58:28it's much closer to the us than
- 58:30than to china but anyway the good news
- 58:33is
- 58:34if you're interested in this type of
- 58:35approach the data requirements
- 58:39to do these types of exercises are
- 58:43relatively mild you don't need a whole
- 58:46lot of data
- 58:48and as i said i think there's a lot to
- 58:50learn
- 58:51from uh doing this type of analysis
- 58:55in different countries right we learned
- 58:58so much
- 59:00by doing this for china right
- 59:03for in some sense i feel that this paper
- 59:07became really interesting when we did
- 59:09the china exercise
- 59:10right just because the comparison uh
- 59:13taught us so many interesting things
- 59:15and again china is obviously just one
- 59:17country it's an important country
- 59:19and it's an interesting country but
- 59:20there's other countries out there
- 59:22you know there's an urbanization is
- 59:24happening everywhere
- 59:26and it's not happening in the same way
- 59:28everywhere right and so
- 59:30you know maybe it is interesting to do
- 59:32some of these exercises in
- 59:34in some african countries that are going
- 59:36through a process of
- 59:38of of urbanization or you can do this
- 59:41for other
- 59:42south asian or south american countries
- 59:45again there's a lot to learn from doing
- 59:48this
- 59:49for for countries that are going through
- 59:51a process of urbanization
- 59:53in some sense there's probably more to
- 59:56learn from those countries than
- 59:57from doing this exercise for france
- 1:00:01or for italy where things are fairly
- 1:00:04stable and so you can probably guess
- 1:00:06more or less what you will find
- 1:00:09okay the other
- 1:00:12is there any quick question before i
- 1:00:14move on
- 1:00:15and talk very briefly about a few other
- 1:00:17papers
- 1:00:23okay uh i i was
- 1:00:26thinking about uh either way we can
- 1:00:29introduce like
- 1:00:30uh friction related to uh human capital
- 1:00:34institutions like only people with
- 1:00:37some minimum level of an educational
- 1:00:40admin
- 1:00:42are allowed to be in a place as opposed
- 1:00:44to
- 1:00:45people who are lord uh
- 1:00:48other do they create more productive
- 1:00:52cities or yeah so
- 1:00:56so i so you're asking about whether
- 1:00:59there's any role in these models for
- 1:01:01human capital right yeah um
- 1:01:04yes there is i mean we we obviously in
- 1:01:07the paper that i have presented
- 1:01:09i haven't said anything about human
- 1:01:11capital but there is a large
- 1:01:14and growing literature in in urban
- 1:01:17economics
- 1:01:18that has been looking at what they call
- 1:01:22sorting right and it's typically sorting
- 1:01:25of people with different skills to
- 1:01:28different types of cities
- 1:01:30right so you're absolutely right that
- 1:01:32cities are
- 1:01:33different not just because of some kind
- 1:01:35of exogenous level of productivity
- 1:01:38they're also different because they
- 1:01:39attract different type of people
- 1:01:42and there's growing interest in that so
- 1:01:44for a while if you go back say 50
- 1:01:4660 yards the typical urban
- 1:01:50the the urban models that were looking
- 1:01:52at city specialization
- 1:01:54uh they were they would typically look
- 1:01:58at
- 1:01:58sexual specialization they would say oh
- 1:02:00that city
- 1:02:01produces cars and the other city
- 1:02:03produces furniture and the third city
- 1:02:05produces something else
- 1:02:07now there's much more interest
- 1:02:10in not really what they call sexual
- 1:02:12specialization but
- 1:02:14a functional specialization and sorting
- 1:02:17of
- 1:02:18people of different skills to different
- 1:02:21cities
- 1:02:22right so what makes a city an attractive
- 1:02:26place
- 1:02:27for someone who's highly educated right
- 1:02:31and it's a very important question and
- 1:02:32city governments are obviously super
- 1:02:34interested in that because they all want
- 1:02:36to track those types of people
- 1:02:38maybe they are looking for urban
- 1:02:39amenities right maybe
- 1:02:41they're looking for like-minded people
- 1:02:44and because of that you get these you
- 1:02:47get these phenomena
- 1:02:48of sorting right so people people want
- 1:02:50to live in a place
- 1:02:52partly the sorting happens because of
- 1:02:54productive reasons but partly the
- 1:02:55sorting also happens because of
- 1:02:57uh utility and consumption reasons right
- 1:03:00there's
- 1:03:01people may just want to live in a
- 1:03:02particular area or particular city or
- 1:03:04particular neighborhood
- 1:03:06because they find like-minded people
- 1:03:08right and so
- 1:03:09uh being attractive for human capital is
- 1:03:12is interesting again in this particular
- 1:03:15paper
- 1:03:16we we didn't consider a heterogeneity
- 1:03:18and skill
- 1:03:19but that's something that could be
- 1:03:21introduced and as i said there's
- 1:03:22there's lots of interest in urban
- 1:03:24economics in those in those types of
- 1:03:26questions
- 1:03:28thank you yeah thank you a really quick
- 1:03:31one for you
- 1:03:32um in in these models does zipf's law
- 1:03:35hold
- 1:03:35for city size distribution um
- 1:03:39that's a that's uh that's an interesting
- 1:03:41question so
- 1:03:42so yes it i mean the zips law holds
- 1:03:46as you know for for typically for for
- 1:03:49pretty much
- 1:03:49all the city sizes and size distribution
- 1:03:52so
- 1:03:53so yes typically it holds where
- 1:03:55sometimes it breaks down a little bit
- 1:03:58is at the very upper end you know so
- 1:04:01there's some if you look say at the top
- 1:04:03three or top four cities across the
- 1:04:06in different countries it's not obvious
- 1:04:08that zips law
- 1:04:09holds there you know you have some
- 1:04:12countries where the
- 1:04:13where the biggest city really has say
- 1:04:15half of the population
- 1:04:17and then the ones that kind of fall
- 1:04:19below that
- 1:04:20uh don't quite uh you know so so the
- 1:04:24at the very upper tail it doesn't
- 1:04:26doesn't necess doesn't necessarily hold
- 1:04:28ziploc
- 1:04:28but but let's say in in the model that
- 1:04:30we present
- 1:04:31there's nothing that that generates
- 1:04:34zips law i'm just more talking about
- 1:04:37does it hold in the data
- 1:04:39right there's there's nothing in the
- 1:04:40model because the model is not really a
- 1:04:42model of
- 1:04:43of of dynamics right so so
- 1:04:47there's lots of interesting models that
- 1:04:49urban models that
- 1:04:51generate zips law you know they sort of
- 1:04:53have a model where
- 1:04:54there's particular shocks that happen
- 1:04:56and these shocks over time
- 1:04:58lead to a city-sized distribution that
- 1:05:01that actually satisfies
- 1:05:03zip's law this this is a very
- 1:05:05interesting literature as well and
- 1:05:07we should probably let you move ahead
- 1:05:08here yes let me move ahead and
- 1:05:11i just want to in the second part in the
- 1:05:13remaining 10 or 12 minutes that i have
- 1:05:16i want to mention a couple of other
- 1:05:18issues in urban
- 1:05:20economics and development just to
- 1:05:21broaden the discussion a little bit
- 1:05:23okay so uh
- 1:05:27so let me start with a handbook chapter
- 1:05:30that i wrote with vern henderson a
- 1:05:34couple of years ago
- 1:05:35where we kind of look at the question of
- 1:05:38what do we know
- 1:05:39about the spatial distribution of
- 1:05:41population
- 1:05:42and how that changes with development
- 1:05:46and so one approach that we'll be very
- 1:05:49familiar with you
- 1:05:50for you because you've studied a
- 1:05:52structural transformation in so much
- 1:05:54detail
- 1:05:55over the past weeks and months
- 1:05:59is there there's there's models where we
- 1:06:02say okay
- 1:06:03if the income elasticity for food is
- 1:06:06less than one
- 1:06:07then of course development will lead to
- 1:06:11industrialization
- 1:06:12right and when development leads to
- 1:06:15industrialization
- 1:06:17then kind of that also implies
- 1:06:20urbanization
- 1:06:21to the extent that industry tends to be
- 1:06:23more urbanized than agriculture
- 1:06:25right of course another approach which
- 1:06:28you're also familiar with from your
- 1:06:29classes on
- 1:06:31structural transformation is you can
- 1:06:34make the assumption that the elasticity
- 1:06:36between food and non-food is less than
- 1:06:38one
- 1:06:38in that case industrialization
- 1:06:42results from higher productivity growth
- 1:06:45and agriculture
- 1:06:46and so uh that kind of uh
- 1:06:50that kind of means that to have an to
- 1:06:54have
- 1:06:54industrialization or to have an
- 1:06:56industrial revolution if you wish
- 1:06:58you need to first have an agricultural
- 1:07:00revolution
- 1:07:01right and so you get you get
- 1:07:03productivity growth in agriculture that
- 1:07:05moves people into dust industry an
- 1:07:08industry
- 1:07:09is simply more urbanized than
- 1:07:11agriculture and that's partly because
- 1:07:14of course industry is less land
- 1:07:16intensive right
- 1:07:18so it tends to be more concentrated and
- 1:07:21secondly it may also be more
- 1:07:23concentrated because there's more
- 1:07:26benefits
- 1:07:27from proximity in industry than there is
- 1:07:30in in agriculture okay
- 1:07:34now if you move a little bit forward and
- 1:07:36say what has happened in
- 1:07:38say the last decades in the u.s and in
- 1:07:41some other
- 1:07:42developed countries what we see is that
- 1:07:46although industry yes urbanized
- 1:07:50in the early time period if you look
- 1:07:53more recently
- 1:07:54we see growing spatial dispersion of
- 1:07:58manufacturing
- 1:07:59manufacturing is still relatively
- 1:08:01concentrated but it's becoming less
- 1:08:02concentrated across space across
- 1:08:04over time whereas with services we're
- 1:08:07seeing the opposite
- 1:08:08right services typically used to be sort
- 1:08:11of the industry as you know which was
- 1:08:13non-tradable and you know wherever
- 1:08:14people live
- 1:08:16where wherever people live you have
- 1:08:17services so services extremely spread
- 1:08:19across space
- 1:08:20but we see growing spatial concentration
- 1:08:24of services and again that that may be
- 1:08:27related to land intensity
- 1:08:30which i said was lower in manufacturing
- 1:08:32than in agriculture but it's of course
- 1:08:34even lower
- 1:08:35in services than it is in industry and
- 1:08:38so
- 1:08:38services are displacing manufacturing
- 1:08:41in cities and then manufacturing is
- 1:08:43becoming geographically more
- 1:08:46dispersed it may also have something to
- 1:08:48do with the life cycle of industries
- 1:08:51right as industry matures
- 1:08:54uh there is less need to be
- 1:08:58close to each other because closeness is
- 1:09:00particularly important in the
- 1:09:02when you're learning right when when
- 1:09:05when technology
- 1:09:06is new and there's a lot of innovation
- 1:09:08there's a lot of benefits
- 1:09:09from proximity that maybe that's more
- 1:09:12true now in some service industries than
- 1:09:14it is in
- 1:09:15manufacturing industries and so these
- 1:09:17manufacturing industries
- 1:09:18no longer need to be spatially
- 1:09:20concentrated
- 1:09:21and are dispersing versus services that
- 1:09:24are becoming more
- 1:09:26concentrated and that's a similar
- 1:09:28pattern you know we looked at this in
- 1:09:30the u.s and we've looked at this in
- 1:09:32europe
- 1:09:32other people have looked at this in
- 1:09:34other countries for example in korea
- 1:09:36that's something that's very well
- 1:09:37documented so when industrialization
- 1:09:39happened in korea
- 1:09:41seoul was the main manufacturing center
- 1:09:44uh in the last decades that's no longer
- 1:09:46true
- 1:09:47what we've seen is industry moving out
- 1:09:50of seoul
- 1:09:50into into uh other areas
- 1:09:54um okay now let me uh
- 1:09:57switch quickly to something else here i
- 1:10:00just want to uh
- 1:10:02very briefly discuss a paper by by doug
- 1:10:05and uh remy genwa bandits fall route
- 1:10:09who looked at this at this very
- 1:10:12interesting observation
- 1:10:13right where you know as i said in the
- 1:10:15previous slides
- 1:10:17the the standard the standard view has
- 1:10:20been
- 1:10:21development leads to industrialization
- 1:10:23industrialization
- 1:10:25implies urbanization what they
- 1:10:27documented in a paper is that
- 1:10:30there are many places in africa
- 1:10:34and in the middle east where we see huge
- 1:10:37increases in urbanization
- 1:10:39without seeing big increases in
- 1:10:41industrialization
- 1:10:42and and and the way they explain this is
- 1:10:45that what really matters for
- 1:10:48urbanization is growing income right
- 1:10:51and growing income does not necessarily
- 1:10:54have to come from industrialization
- 1:10:56growing income could also come for
- 1:10:57instance from having a
- 1:10:59higher income from natural resources and
- 1:11:01so the sort of idea
- 1:11:03is that okay we have natural resources
- 1:11:06say
- 1:11:06gas or oil our income goes up
- 1:11:11we're not industrializing but as our
- 1:11:13income improves
- 1:11:14and grows we want to spend our income on
- 1:11:17stuff
- 1:11:18right and we want to live in a city uh
- 1:11:21to enjoy the city
- 1:11:22to be able to spend money in the city
- 1:11:24and so this is kind of the idea that
- 1:11:27when we think about cities and
- 1:11:29development
- 1:11:30we shouldn't think only about cities and
- 1:11:33development
- 1:11:35cities being productive centers
- 1:11:38cities are also consumption centers
- 1:11:40right and
- 1:11:41and that's true in some of these places
- 1:11:43in africa in the middle east
- 1:11:44it's it's actually also true in some of
- 1:11:46uh
- 1:11:47some of the developed countries right i
- 1:11:49mean there's there are many
- 1:11:51people some of the rich people in the
- 1:11:53world
- 1:11:54who want to move to say a city like
- 1:11:56london
- 1:11:57not to be productive they just want to
- 1:11:59live in london to enjoy london
- 1:12:01right of course london is a very
- 1:12:02productive city right because
- 1:12:04lots of people are working there but
- 1:12:06there's a growing uh
- 1:12:08share of the population or just there to
- 1:12:11enjoy the place
- 1:12:12right and so if you have a lot of money
- 1:12:14you also want to spend it where can you
- 1:12:15spend it well you can spend it in
- 1:12:17in some of these uh big big cities
- 1:12:21okay i'm i'm i'm slowly going to um
- 1:12:25be wrapping up here uh but i wanted to
- 1:12:28mention
- 1:12:29just a few more things uh another really
- 1:12:32interesting paper
- 1:12:33uh recent paper on development
- 1:12:37and and space is this paper by henderson
- 1:12:41and others
- 1:12:42in the qje so what they look is what are
- 1:12:45the
- 1:12:45what they look at is what are the
- 1:12:47determinants of the global distribution
- 1:12:49of economic activity
- 1:12:51right and so they look at the entire
- 1:12:53planet and they look
- 1:12:54they use satellite lights right to
- 1:12:56measure the level of development
- 1:12:58or the level of the distribution of
- 1:13:00economic activity across space
- 1:13:02and they say let's kind of look at two
- 1:13:05groups of determinants
- 1:13:07let's think about the permanence that
- 1:13:09are important for agriculture
- 1:13:11so maybe the soil quality or the
- 1:13:14temperature or whatever or the
- 1:13:15precipitation so you look at certain
- 1:13:18factors or determinants that are
- 1:13:19important for agriculture productivity
- 1:13:22and then they look at certain
- 1:13:23determinants that are important for
- 1:13:25trade
- 1:13:26meaning access how well am i connected
- 1:13:30to the rest of the world maybe am i a
- 1:13:32port am i on a big river
- 1:13:34that that facilitates trade and they
- 1:13:36come up
- 1:13:37with a very then they run a bunch of
- 1:13:39regressions but they come up with a very
- 1:13:40puzzling finding
- 1:13:42which is that it turns out
- 1:13:45that agriculture so this group of
- 1:13:47variables which we could call
- 1:13:49agricultural determinants explains much
- 1:13:51more of the variation
- 1:13:54in the spatial distribution of economic
- 1:13:57activity
- 1:13:58in developed countries than in
- 1:13:59developing countries
- 1:14:01it's puzzling in the sense that you
- 1:14:03would say well in developed countries
- 1:14:05nobody is doing agriculture anymore
- 1:14:07how come agriculture seems to determine
- 1:14:09where people live
- 1:14:10and i go to developing countries but
- 1:14:12agriculture is still very important
- 1:14:14and there it matters a lot less than in
- 1:14:16developed countries
- 1:14:17and so the explanation they come up with
- 1:14:20is that
- 1:14:21in the early developers let's say
- 1:14:24today's advanced economies
- 1:14:26structural transformation out of
- 1:14:29agriculture into industry
- 1:14:31happened at a time when transportation
- 1:14:34costs were still very high
- 1:14:36and and that means that at that time
- 1:14:39cities
- 1:14:40tended to be located in agriculture
- 1:14:43regions right
- 1:14:44so just sort of go back 200 or 300 years
- 1:14:47right and think about it in the
- 1:14:49following way
- 1:14:51where did cities grow cities grew in
- 1:14:53places where it was agricultural surplus
- 1:14:56right so that there was enough to eat
- 1:14:58for everyone
- 1:14:59and some people could start doing other
- 1:15:01stuff so they moved into cities
- 1:15:04to dedicate themselves to other
- 1:15:06productive activities
- 1:15:07but of course once they were in these
- 1:15:09cities they still needed to eat
- 1:15:10right and so where did they get the food
- 1:15:12from they sourced that food
- 1:15:14locally right and
- 1:15:18and they had to source it locally
- 1:15:20because transportation costs were still
- 1:15:22very high
- 1:15:23and so the point is that in advanced
- 1:15:26economies
- 1:15:27cities tended to emerge in places that
- 1:15:30had a productive agricultural hinterland
- 1:15:33versus in less developed countries or
- 1:15:36later developers if you wish
- 1:15:38where trade was already relatively cheap
- 1:15:42that wasn't really needed and so cities
- 1:15:44could emerge
- 1:15:45in places that didn't necessarily have
- 1:15:47have have an agricultural hinterland
- 1:15:50let me wrap up with one last thought
- 1:15:53here
- 1:15:54uh related to a space and
- 1:15:57sector of specialization etc um
- 1:16:00i will just take one minute i realize
- 1:16:03i'm going a little bit over time here
- 1:16:05but i've been working in the last years
- 1:16:07quite a bit
- 1:16:09on models uh spatial models
- 1:16:13of uh climate change right and so
- 1:16:17why is that interesting in the context
- 1:16:19of
- 1:16:20this course i think well of course
- 1:16:22because
- 1:16:24on the one hand you need to think about
- 1:16:26space
- 1:16:27because different places are going to be
- 1:16:29affected differently
- 1:16:31by global warming but you also need to
- 1:16:34think about sectors
- 1:16:35because obviously agriculture depending
- 1:16:38on where you are
- 1:16:39may be much more affected by global
- 1:16:41warming than other sectors
- 1:16:43right and so we will see big
- 1:16:46shifts in where different things
- 1:16:50are going to be produced
- 1:16:53because of because of climate shocks
- 1:16:56right and so we can look at
- 1:16:57you know different maps and we can do
- 1:16:59different things
- 1:17:00with these types of models on you know
- 1:17:03here this last thing here is
- 1:17:05looking at uh in the earth 2200
- 1:17:10where when agric cultural output
- 1:17:12happened this is part b
- 1:17:15in in a world without climate change
- 1:17:17versus in a world with climate change
- 1:17:19which would be c
- 1:17:21so so that's very interesting i think as
- 1:17:23well sort of thinking about
- 1:17:24not just urban and space but think
- 1:17:28urban space plus sectors right
- 1:17:30agriculture versus other sectors
- 1:17:32how that might be impacted by climate
- 1:17:35change
- 1:17:36i'm going to stop here i went a little
- 1:17:38bit over time and i'm happy to take
- 1:17:41any questions you might have
- 1:17:45fantastic thanks a ton klaus um
- 1:17:48let me open things up to the front row
- 1:17:50first
- 1:17:54hi close thanks for the presentation
- 1:17:57really interesting
- 1:17:58um going back to the that first model
- 1:18:01where you have the ait
- 1:18:02term for cities i guess how would you
- 1:18:06think about making it endogenous because
- 1:18:08i could imagine so
- 1:18:09actually one thing we we did do and i
- 1:18:12didn't mention
- 1:18:13uh we did a number of exercises where we
- 1:18:17endogenized aid in the following sense
- 1:18:21as you know in in urban economics and in
- 1:18:23economic geography
- 1:18:26there is a lot of evidence that
- 1:18:29ait is made up of two components
- 1:18:33one is kind of exogenously given
- 1:18:37maybe relates to one of the questions we
- 1:18:39had before
- 1:18:40you know maybe you know you have better
- 1:18:42amenities so you have
- 1:18:43you have better endowments or you're in
- 1:18:46a more favorable location
- 1:18:48we could think of that as being
- 1:18:50exogenous and then
- 1:18:51an endogenous component that is related
- 1:18:56to size right so bigger cities
- 1:19:00uh tend to be more efficient because
- 1:19:03they're bigger
- 1:19:04right and there's a lot of estimates out
- 1:19:06there and typically the estimates
- 1:19:08range somewhere between an elasticity of
- 1:19:11somewhere between
- 1:19:13point zero two and point zero six
- 1:19:16meaning
- 1:19:17when you double a a city in size
- 1:19:20the productivity would go up by
- 1:19:23somewhere between
- 1:19:24two and six percent so so that's the way
- 1:19:26in which we endogenize
- 1:19:28the ait you could of course go to a
- 1:19:31fully
- 1:19:32dynamic model in which you also
- 1:19:35think about innovation and incentives to
- 1:19:38innovate
- 1:19:39and how that may be different across the
- 1:19:42cities because different cities have
- 1:19:44different markets
- 1:19:45and if i'm in a bigger market i may have
- 1:19:47a
- 1:19:48greater incentive to uh to engage in
- 1:19:50local innovation
- 1:19:52uh that is actually this last couple of
- 1:19:55slides that i showed you
- 1:19:56these models with climate change uh
- 1:19:58actually also
- 1:20:00those are fully dynamic and look at at
- 1:20:03the
- 1:20:03incentives to innovate in in the in the
- 1:20:06paper on urban
- 1:20:07with the ait there we endogenize
- 1:20:11simply in terms of bringing in city size
- 1:20:15as an additional determinant of city
- 1:20:18productivity
- 1:20:21thank you yeah
- 1:20:24that was a question from stephen barlow
- 1:20:27in the q a
- 1:20:28really kind of a complex of questions
- 1:20:31about
- 1:20:32covin and um
- 1:20:35the extent to which we may be seeing a
- 1:20:38change in the pattern of people working
- 1:20:39in city centers
- 1:20:41how much does that motivate a rethinking
- 1:20:44of the standard urban model
- 1:20:47so that that's a really fascinating
- 1:20:50question
- 1:20:51and and now we'll answer it maybe in two
- 1:20:53different ways so
- 1:20:55um i was recently reading a paper by
- 1:20:59nick bloom and some other people at
- 1:21:01stanford
- 1:21:02about you know will will work at home
- 1:21:06will that stay or will it not stay and i
- 1:21:08think they come up with some kind of
- 1:21:10number that
- 1:21:11probably uh 20 percent uh
- 1:21:14they will 20 of work will be done from
- 1:21:17home uh
- 1:21:18now the very important question when we
- 1:21:20say 20
- 1:21:21just to say a number right suppose we
- 1:21:23say 20 will will be done from home
- 1:21:26it's very different if you say
- 1:21:29every individual will say work
- 1:21:33four days in the office and one day at
- 1:21:36home
- 1:21:37versus saying 80 of the individuals
- 1:21:41will work five days a week in the office
- 1:21:43and twenty percent of the individuals
- 1:21:45were work
- 1:21:46all five days from home uh if you take
- 1:21:49those two
- 1:21:50uh cases they would have very very
- 1:21:53different implications
- 1:21:54for uh for city sizes right and for the
- 1:21:58urban model so
- 1:21:59if if i take the second case which i
- 1:22:02sort of feel is a more reasonable one
- 1:22:03but i'm not 100 sure
- 1:22:05if you sort of say we'll move to a model
- 1:22:07where
- 1:22:08many people will work one day a week or
- 1:22:11maybe two days a week from home
- 1:22:14then you could imagine that cities may
- 1:22:16actually become a lot larger
- 1:22:18right because the easiest way of
- 1:22:20modeling that would simply to say look
- 1:22:22my commuting costs are going to go down
- 1:22:24by 20 or my 40 percent
- 1:22:26and you know if i need to commute every
- 1:22:28day an hour in
- 1:22:30an hour out that's too much i mean the
- 1:22:33average commute in america is about
- 1:22:3530 minutes in and 30 minutes out it
- 1:22:38seems like
- 1:22:39more than 30 minutes people don't have a
- 1:22:40lot of patience for that
- 1:22:42but but if you only have to do this
- 1:22:43three days a week
- 1:22:45you may be perfectly happy with 45 60
- 1:22:47minutes
- 1:22:48it's okay right if you do this three
- 1:22:49days a week and so cities could actually
- 1:22:52become
- 1:22:52a lot larger because the urban costs are
- 1:22:56going down because you
- 1:22:57don't need to do it every eve every day
- 1:23:00versus
- 1:23:01the other model where you say no no this
- 1:23:04is going to be 20 of people who will
- 1:23:06never go into the office
- 1:23:08well then of course those those 20
- 1:23:10become completely footloose
- 1:23:12they could be anywhere right and we've
- 1:23:14always had some
- 1:23:15part of the labor force you know people
- 1:23:17working you know as
- 1:23:18telephone uh how i answered telephones
- 1:23:20and customer service
- 1:23:22they may just be living in a small city
- 1:23:24somewhere in uh
- 1:23:26in anywhere really right and they don't
- 1:23:28need
- 1:23:29they don't need any of that urban urban
- 1:23:32they don't need any of that urban
- 1:23:33environment so
- 1:23:34so depending on where we're heading the
- 1:23:38the the the the effects may be quite
- 1:23:41different
- 1:23:42another another small
- 1:23:45thing related to covet is
- 1:23:48there is some evidence
- 1:23:52that there is again a growing demand
- 1:23:56for living in the suburbs
- 1:23:59because there's growing demand for space
- 1:24:02right and so that may also of course
- 1:24:05change the structure of cities
- 1:24:07right in the following sense in our
- 1:24:10model
- 1:24:10i made the assumption that every
- 1:24:13individual lives on one unit of land
- 1:24:16that's obviously a simplifying
- 1:24:17assumption right it's true that
- 1:24:20as you move away from the city center
- 1:24:23people tend to live on bigger and bigger
- 1:24:25plots of land
- 1:24:26right if you bring that into the model
- 1:24:29and if you start thinking that
- 1:24:31the demand for space there's a shock to
- 1:24:34the demand for space
- 1:24:36because i'm going to be working more at
- 1:24:37home for example right
- 1:24:39i need some more space if i'm going to
- 1:24:41need a home office
- 1:24:43that may change that rent gradient and
- 1:24:46that may change
- 1:24:49the compactness of cities and there may
- 1:24:51be some effects
- 1:24:52there may be some effects there as well
- 1:24:55another
- 1:24:56related and i'll stop here because i
- 1:24:57realize there may be some other
- 1:24:58questions but
- 1:24:59another really interesting uh question
- 1:25:02at least to me is
- 1:25:04what is going to happen to these
- 1:25:07agglomeration economies right
- 1:25:10so so you know if you look at
- 1:25:14agglomeration economies as i said these
- 1:25:16are the conglomerations you get from
- 1:25:17density
- 1:25:18but but we as economists we think of
- 1:25:20those economies as being external
- 1:25:23right they're externalities they're
- 1:25:25external to the individual
- 1:25:26they may even be external to the firm so
- 1:25:29if you allow
- 1:25:30individuals to choose whether they go to
- 1:25:33work
- 1:25:34or not go to work or even if you allow
- 1:25:36firms to tell people what they should do
- 1:25:39right those decision makers are not
- 1:25:42fully internalizing
- 1:25:44these agglomeration economies so there
- 1:25:47may be some
- 1:25:49there may be some bad surprises in terms
- 1:25:52of productivity if
- 1:25:54if this is taken to an extreme the
- 1:25:56example would be
- 1:25:57suppose we now all change our
- 1:26:00preferences
- 1:26:00and we all want to stay at home always
- 1:26:03right
- 1:26:05you know it's a very big question what
- 1:26:07would happen to these agglomeration
- 1:26:09economies
- 1:26:10right and i think that's a fascinating
- 1:26:12question and and
- 1:26:14and it's not obvious that that the
- 1:26:16so-called decentralized economy
- 1:26:19will bring us to a place that's
- 1:26:23uh that's good we don't really know
- 1:26:25what's going to happen to that
- 1:26:29any other questions yeah i wanted to ask
- 1:26:33you a quick question
- 1:26:34um actually it's it's sort of true so
- 1:26:37one was a more general question because
- 1:26:39you were saying in on the first part as
- 1:26:41well that
- 1:26:42yeah you don't even need that much data
- 1:26:44to make great analysis using that simple
- 1:26:46model
- 1:26:47but um this said is there any like very
- 1:26:50innovative or interesting data source
- 1:26:53for um
- 1:26:54yeah in the context of urbanization you
- 1:26:56would like
- 1:26:57be able to point out to us um yeah and
- 1:27:00the second
- 1:27:01and the second question i have was
- 1:27:02referring also to this first model
- 1:27:05yeah where it's not entirely clear to me
- 1:27:07how um
- 1:27:08maybe different yeah costs of
- 1:27:12of actual goods in the city might enter
- 1:27:15like
- 1:27:15how differences in prices and not just
- 1:27:17trends
- 1:27:19enter into that model and how they
- 1:27:21matter
- 1:27:23and thank you very much for this awesome
- 1:27:24presentation yes thank you
- 1:27:27so your first question is a fantastic
- 1:27:30question
- 1:27:31and i don't have a very good answer but
- 1:27:34what i
- 1:27:35do what i what i what i can say
- 1:27:38is that the world of
- 1:27:41spatial data is really
- 1:27:44exploding right and so there's
- 1:27:48more and more information available
- 1:27:52at the local level and and people are
- 1:27:55using uh
- 1:27:57very creative ways of
- 1:28:00getting at these data right so so of
- 1:28:02course the one example is using
- 1:28:04satellite data to
- 1:28:06to measure uh local economic activity
- 1:28:10but there's also people who have looked
- 1:28:12at
- 1:28:14at more who've looked at for example
- 1:28:19data on parking lots of
- 1:28:23shopping malls to try to understand the
- 1:28:26retail activity at the local level you
- 1:28:28know how full are those parking lots and
- 1:28:30how
- 1:28:31what does that tell me about uh about uh
- 1:28:35the economic cycle so so so there's more
- 1:28:37and more data
- 1:28:39available at uh at the local level
- 1:28:42uh and and it's really an exploding
- 1:28:45field so i think
- 1:28:46uh doing stuff uh doing spatial
- 1:28:49economics in general is is
- 1:28:52is interesting because there's lots of
- 1:28:53of course interesting questions but
- 1:28:55it's also promising this promising field
- 1:28:58because
- 1:28:59the data are just uh getting better and
- 1:29:02better
- 1:29:03uh over time right and so i think it
- 1:29:06it still requires some doses of
- 1:29:10creativity but when you kind of look
- 1:29:13around
- 1:29:14and you look at how people are creative
- 1:29:16it's really quite
- 1:29:18quite amazing there was recently
- 1:29:21a paper i don't remember where it was
- 1:29:23published
- 1:29:24by some economists uh
- 1:29:28looking at how we can use uh historical
- 1:29:31spatial data to
- 1:29:33think about some of the big questions of
- 1:29:35economic history
- 1:29:37right and so people are using all kinds
- 1:29:39of map
- 1:29:40technologies and all kinds of ways of
- 1:29:43trying to get the information at the
- 1:29:46local level
- 1:29:47you know even going back to say 19 18th
- 1:29:49century
- 1:29:51so it's a it's a very it's it's a very
- 1:29:53uh
- 1:29:55it's a very exciting uh it's a very
- 1:29:57exciting field
- 1:29:59to to be in uh your second question on
- 1:30:03on prices in general i think there's two
- 1:30:07things here one is
- 1:30:08uh in general uh we all know that
- 1:30:13in bigger cities there is more
- 1:30:15competition for land
- 1:30:17and so land prices go up and that
- 1:30:19translates into
- 1:30:20higher housing prices but it just
- 1:30:24typically also translated to higher
- 1:30:26prices in general
- 1:30:28and so a lot of urban economists
- 1:30:31kind of simplify things and just focus
- 1:30:34on
- 1:30:35on house prices as a kind of proxy a
- 1:30:39kind of all-encompassing proxy
- 1:30:41of measuring uh the cost of density that
- 1:30:44that goes to through the lamp price uh
- 1:30:48but but but you're right with that not
- 1:30:50everything is said
- 1:30:51right there's also evidence for instance
- 1:30:53that bigger cities
- 1:30:56uh uh have more competition
- 1:30:59right so because they have more
- 1:31:00competition the prices of certain things
- 1:31:03may actually also be lower
- 1:31:04right so land prices are higher but it
- 1:31:07that doesn't mean that the price of
- 1:31:08every single
- 1:31:09uh product you buy is necessarily higher
- 1:31:12so
- 1:31:13so there's also fascinating literature i
- 1:31:15think on
- 1:31:16on size of market size of local market
- 1:31:19degree of competition how that feeds
- 1:31:22into prices how that feeds into uh
- 1:31:24innovation etc etc
- 1:31:31any uh any other questions
- 1:31:34i have a quick one for you i think it's
- 1:31:36a quick one from
- 1:31:37somash mature in the in the q a do we
- 1:31:40have some better indices
- 1:31:42than um then
- 1:31:46indices of spatial dispersion so um
- 1:31:48obviously hirschmann her selector
- 1:31:50um but what kind of indices do we have
- 1:31:54of dispersion among manufacturing
- 1:31:56services that
- 1:31:57are useful looking at locations
- 1:32:01so i would say two things so if you just
- 1:32:03want to have
- 1:32:04one statistic
- 1:32:08yes so you know you'll use the the
- 1:32:11herschleifer index you can look at uh
- 1:32:14and of course the variance or the
- 1:32:16coefficient of variation
- 1:32:18or the difference between the 80th and
- 1:32:20the 20th percentile so
- 1:32:22all the sort of standard all all the
- 1:32:25sort of standard measures
- 1:32:27but i'll but but what is true as well is
- 1:32:29that
- 1:32:30sometimes it is actually useful to look
- 1:32:33at the entire distribution
- 1:32:35right and so you may sometimes be
- 1:32:37surprised you may think well
- 1:32:38everything is said by increasing or
- 1:32:40decreasing dispersion
- 1:32:42but when you look at the entire
- 1:32:44distribution uh
- 1:32:46you may see some things you you didn't
- 1:32:50expect
- 1:32:50right so it may very well be that that
- 1:32:53for example again that
- 1:32:55that maybe these medium-sized places are
- 1:32:58uh
- 1:32:59are becoming uh are doing particularly
- 1:33:02well
- 1:33:02and that the the both the biggest and
- 1:33:05the smallest and
- 1:33:06the medium small are not doing that well
- 1:33:08so so i would always
- 1:33:10recommend to the extent possible rather
- 1:33:13than immediately going
- 1:33:15to a summary statistic like the ones we
- 1:33:19mentioned
- 1:33:20that i would i would plot the entire
- 1:33:22distribution
- 1:33:23just to see hey is there anything else
- 1:33:25that's interesting so you could for
- 1:33:26example have a situation where the tail
- 1:33:29is becoming a lot fatter or where the
- 1:33:31tail is not become
- 1:33:32where the tail is becoming thinner maybe
- 1:33:34maybe the action is over there
- 1:33:36right and then maybe looking at
- 1:33:38dispersion or concentration is not
- 1:33:40really the right way of
- 1:33:42looking at the data right and so that's
- 1:33:44that would be my
- 1:33:45that would be my recommendation
- 1:33:49i think i should probably in the
- 1:33:51interest of time there's
- 1:33:52there's still always last questions
- 1:33:55coming in but i think in the interest of
- 1:33:57time we should probably close things out
- 1:33:59and so i'd like to thank you klaus and
- 1:34:02i'd also like to turn things over
- 1:34:04to my my partner in crime joe kaboski
- 1:34:07to close out today's lecture and and
- 1:34:09really i guess to close out the whole
- 1:34:11set of lectures so my thanks klaus and
- 1:34:14maybe others can join me first
- 1:34:16before i turn it over to joe maybe those
- 1:34:19in the front row can do what we've been
- 1:34:20doing and unmute
- 1:34:21and let's give klaus uh a round of um
- 1:34:25real as close to real applause as we can
- 1:34:32yeah thank you all it was it was it was
- 1:34:35really fun and i
- 1:34:36i enjoyed it and very good questions too
- 1:34:38i i always worry in these types of
- 1:34:41online settings where there's lots of
- 1:34:43people uh
- 1:34:45how do you get to a good level of
- 1:34:48engagement and interaction and i'm very
- 1:34:50happy that this part this part just
- 1:34:53worked really well so thank you
- 1:34:55thanks and and joe let me turn things
- 1:34:57over to you
- 1:34:58yeah that's a great segue into uh what i
- 1:35:01wanted to say
- 1:35:01i mean the first is that this is the
- 1:35:03last uh lecture of the course
- 1:35:05um uh klaus was the headliner cleanup
- 1:35:09batter and um so i wanted to thank the
- 1:35:12cepr staff
- 1:35:14especially for you know everything that
- 1:35:16they've done
- 1:35:17making this possible uh that's um
- 1:35:21mandy chan kirsty mcneil mcneil
- 1:35:25lauren waring and nadine clark um
- 1:35:28and people you know all through uh cepr
- 1:35:33um this course has really been a
- 1:35:36grand experiment uh not only for cepr
- 1:35:40but i think for the profession
- 1:35:42i know that um next week i'm meeting
- 1:35:45with people for bread
- 1:35:46to try to figure out a similar type of a
- 1:35:50course
- 1:35:50so that we can reach more people um
- 1:35:53i it's in in our minds in doug's and
- 1:35:57in my mind it's been a tremendous
- 1:35:58success i've learned a ton
- 1:36:00uh just from sitting in on these
- 1:36:01lectures um
- 1:36:04but we want to learn more and we'd like
- 1:36:06to get feedback from the students
- 1:36:08so we will be sending out uh and and
- 1:36:10maybe as well from the
- 1:36:12lecturers uh we will be sending out
- 1:36:15an evaluation uh i think
- 1:36:18both uh maybe with an anonymous part and
- 1:36:21a uh identified part because
- 1:36:25we'd also like to sell the idea and so
- 1:36:27if we can get some nice quotes
- 1:36:30with names attached that would be
- 1:36:32wonderful
- 1:36:34but we also want to learn how to improve
- 1:36:35the course
- 1:36:37are there ways to like klaus said are
- 1:36:39there ways to improve
- 1:36:40engagement um we we need to find out uh
- 1:36:44you know
- 1:36:45where things went right and where they
- 1:36:46went wrong so i just want to thank you
- 1:36:48all
- 1:36:49of course it's you know always the
- 1:36:51people that hang out until the very end
- 1:36:52are
- 1:36:53only a fraction of the overall people um
- 1:36:56but i want to thank you guys especially
- 1:36:59and
- 1:36:59uh please give us feedback so we can
- 1:37:01learn from this
- 1:37:03thanks klaus as well bye-bye
- 1:37:12thanks everyone we look forward to
- 1:37:14hearing from you all
- 1:37:15and to staying in touch so many many
- 1:37:18thanks
- 1:37:20all the students all the people who've
- 1:37:21been attending it's
- 1:37:23it's uh it's been great to get to know
- 1:37:25many of you over the past weeks too
- 1:37:28so look forward to staying in touch
- 1:37:33bye everyone
- 1:38:34you
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YouTube2Text is a free YouTube transcript generator — no signup, no daily limit. Paste any YouTube link and get the full transcript instantly, with timestamps, click-to-jump, caption language selection, AI prompts for ChatGPT, Claude, and Gemini, and exports to TXT, SRT, VTT, or Markdown.