ECON 20110 Fall 2013 - Lecture 13: Redistribution — Transcript
Full transcript
- 0:01okay let's get started so
- 0:05um today we're going to apply Monopoly
- 0:08Theory to I think a very important
- 0:10social problem which is the growing
- 0:13inequality uh in the United States uh um
- 0:17as well as many other countries and I'm
- 0:19going to talk about why one might be
- 0:21concerned about this um even from sort
- 0:25of a Libertarian perspective why
- 0:27redistribution might be valuable because
- 0:30it provides insurance against risks that
- 0:33people would have chosen to insure
- 0:35themselves against if they had the
- 0:36opportunity to do so but that they don't
- 0:38have the opportunity to
- 0:40do um and I'll talk about from that
- 0:43perspective what
- 0:45optimal Insurance should try to do
- 0:48maximizing people's expected
- 0:50utilities and that uh concave utility as
- 0:54a function of wealth means that the poor
- 0:57value a marginal dollar more than the
- 0:58rich do and therefore that
- 1:00redistribution is valuable and we'll
- 1:02talk about logarithmic utility as a good
- 1:04approximation to this we'll then build a
- 1:06framework for analyzing optimal
- 1:09Taxation and we'll analyze two things in
- 1:12that context first uh the optimal linear
- 1:16or sort of average tax rate that people
- 1:18pay so you know in reality tax schedules
- 1:21are like you know you pay a certain rate
- 1:23on the first certain amount of income
- 1:25more on the next certain amount etc
- 1:28etc um but you can think of the optimal
- 1:31linear tax as a measure of um sort of
- 1:35what the average tax rate should be and
- 1:37we'll calibrate that using a log
- 1:40logistic distribution of income which is
- 1:42a reasonably good fit to the US income
- 1:44distribution then we'll also talk about
- 1:46the optimal special sear charge for the
- 1:48rich so I don't know if you guys
- 1:50remember but a few years ago Obama was
- 1:52talking about introducing an extra tax
- 1:54on people earning over a million dollar
- 1:56and we'll talk about uh what what that
- 1:58should be and we'll calibrate that using
- 2:01the fact that at the top end of the
- 2:02income Spectrum the distribution of
- 2:04incomes is roughly
- 2:06Paro um like those fat tail
- 2:08distributions we talked about and then
- 2:10we'll talk about evidence on labor
- 2:12Supply elasticity which is the other key
- 2:14parameter other than inequality in
- 2:17determining optimal
- 2:18redistribution and then finally I'll
- 2:20talk a little bit about an alternative
- 2:22theory of optimal income taxation that
- 2:25um that I've been developing with some
- 2:28co-authors recently okay so income
- 2:31inequality uh can be measured in roughly
- 2:35three broad types of ways one is income
- 2:38inequality at the very bottom of the
- 2:39distribution the second is income
- 2:41inequality throughout the main part of
- 2:42the distribution and the third is at the
- 2:44very top so poverty me measures
- 2:47inequality at the very bottom and this
- 2:49is typically measured by the fraction of
- 2:50individuals who are below some line um
- 2:54so there's a global poverty line of $1
- 2:57per day but uh that's not really a
- 3:01reasonable or useful measure in the
- 3:02United States where people are so much
- 3:04richer so in the United States there's
- 3:06also sort of a relative poverty line
- 3:08which measures this inequality at the
- 3:10bottom and the interesting thing is
- 3:12despite the fact that we'll talk about
- 3:14um how inequality is been growing uh
- 3:17poverty in the United States has not
- 3:19been growing in fact it's been declining
- 3:22so uh inequality at the bottom end of
- 3:24the spectrum has not been grown on the
- 3:26other hand inequality in the mid-range
- 3:29is usually measured by the Genny
- 3:31coefficient which is a measure of how
- 3:34far from perfect equality the economy is
- 3:36and let me just show you what that looks
- 3:38like so um this curve here is called the
- 3:43Loren curve this says if we consider the
- 3:46bottom say 50% of people in the
- 3:49population what fraction of all of the
- 3:52income do they earn if there was perfect
- 3:54equality that would be 50% right then
- 3:57you can get you know at the bottom 7 %
- 4:00what fraction do they earn Etc that
- 4:02draws out this thing called Loren curve
- 4:04and then the geny coefficient is the
- 4:07area above the Loren's curve and below
- 4:09the line of perfect equality divided by
- 4:12the total area of this
- 4:15triangle yep has there been any Research
- 4:17into what is the optimal level of
- 4:21inequality on any kind of meure uh yeah
- 4:24there's a ton of stuff about that um
- 4:26there's a whole literature on whether
- 4:28inequality or to what extent inequality
- 4:30might increase or decrease growth one
- 4:33way of thinking about that is exactly
- 4:34what we're going to study today which is
- 4:37how much redistribution should you do
- 4:40but you know the question when you say
- 4:42optimal is optimal with respect to what
- 4:44intervention you know what I mean
- 4:46because like how would one change
- 4:48inequality well one way you could do it
- 4:50is by taxing and redistributing another
- 4:53way you could do it is by killing off
- 4:56all the poor
- 4:57people another way you could do it is by
- 5:00not killing off all the poor people but
- 5:01stopping any poor people from having
- 5:03children so I mean there are many
- 5:05different interventions and to really
- 5:07talk about the optimal extent of
- 5:09inequality you need to say optimal with
- 5:11respect to like what particular policy
- 5:13intervention that could change it so
- 5:15yeah I guess a related question is why
- 5:17is it that when they that um you're
- 5:21measuring this so when you do your gain
- 5:23coition it's with respect to perfect
- 5:24equality so why is it necessarily that
- 5:27as close to a some level of inequality
- 5:29well because it's just trying to measure
- 5:31how much inequality there
- 5:33is it's not attempting to say what it
- 5:37should be it's just measuring the degree
- 5:39of inequality so it's a it's a purely
- 5:41positive measure not a normative
- 5:45measure okay so
- 5:48um the the second uh the last measure is
- 5:54top income
- 5:56shares so this is what part of income
- 5:59does the do the richest people take so
- 6:03you might ask what fraction does the top
- 6:0410% take of all income top 1% and this
- 6:08measures inequality at the very uh high
- 6:11end of the spectrum as well so this has
- 6:14been growing radically in recent years
- 6:17in the United States and it's mostly at
- 6:19the very very top so this shows over the
- 6:22years what fraction of national income
- 6:25is acing to the top 1% the top 5 to 1%
- 6:30and the top 10 to 5% and as you'll
- 6:32notice there's been a little bit of
- 6:33increase in the top 5 to 1% hardly any
- 6:36increase in the top 10 to 5% and the top
- 6:391% has just
- 6:42skyrocketed but in other countries
- 6:46that's not uh true so if you look at the
- 6:49top 1%
- 6:51share in France it's come down and
- 6:54stayed down in Japan it's come down and
- 6:57stayed down Etc
- 7:02okay um
- 7:05and if you look at inequality at a a
- 7:08global
- 7:09scale the only part of it that's been
- 7:12increasing is the number of people that
- 7:14are super
- 7:16rich whereas overall geny coefficient
- 7:18has increased a little bit uh but not
- 7:21very much um especially not in recent
- 7:25years and um uh the fraction
- 7:30uh Super Rich that are coming from the
- 7:32United States is actually not increased
- 7:34because there come to be a lot more
- 7:36super rich people in other uh
- 7:38countries okay so many Libertarians and
- 7:43conservatives tend to oppose
- 7:45redistribution and I used to be uh one
- 7:48of these so I sort of emphathize with
- 7:50these ideas uh and let me go through
- 7:53what some of their standard arguments
- 7:55against redistribution are so one the
- 7:58most common one is that you know rich
- 7:59people earn their money so who has the
- 8:01right to take it away from them another
- 8:03argument that you hear a lot is social
- 8:05Darwinism which is that rich people are
- 8:08better than other people uh that's why
- 8:11they got rich and if we want the society
- 8:13to be healthy to work you know Etc we
- 8:15need to have more uh of them that could
- 8:18either mean that we want them to have
- 8:19more children and we think if they have
- 8:20more money they'll have more children it
- 8:22could also be that we think that they're
- 8:24better at using that money in a
- 8:26productive way poor people will just
- 8:27piss that money away or whatever the
- 8:29rich people use it for productive
- 8:32Investments another argument from Robert
- 8:36nosek uh is that um if they got their
- 8:41money in a fair way who has the right to
- 8:43take it away from them like if we
- 8:44started with an initially Fair situation
- 8:47and we enforced Fair rules along the way
- 8:49and some people got rich that well
- 8:51that's just the outcome of a bunch of
- 8:53fair things happening and so it couldn't
- 8:55be unfair another argument is that
- 9:00a Protestant argument is that the
- 9:02wealthy are wealthy because they were
- 9:04chosen by God and you know man should
- 9:06not undo what God
- 9:08chose Ein Rand argues that taxation is a
- 9:11form of violence and that property is
- 9:13basically inviable it's another standard
- 9:16libertarian perspective there are sort
- 9:19of fascistic arguments for uh against
- 9:22redistribution that basically
- 9:24redistribution encourages people to have
- 9:26conflicts between classes and that it's
- 9:28important to like Unity within a society
- 9:31and in order to do that uh we have to um
- 9:34avoid uh redistribution conservatives
- 9:38tend to argue that every like element of
- 9:41society has a role to play Within
- 9:43society and that redistribution can
- 9:45upset the ability of those traditional
- 9:48groups to play their relevant roles now
- 9:51um I think some of these arguments are
- 9:53quite interesting and powerful and I'm
- 9:55going to try to return a little bit to
- 9:57them later um
- 10:00and a lot of them haven't really been
- 10:01modeled that well by
- 10:03economists uh but I think that there's a
- 10:06pretty compelling argument even for a
- 10:09Libertarian for redistribution and in
- 10:11fact when I was a Libertarian it was
- 10:13this argument that originally persuaded
- 10:15me that redistribution might be
- 10:18desirable and it's very related to a
- 10:21classic Christian saying by John
- 10:24Bradford so he saw poor people being led
- 10:28through the streets uh to like a
- 10:30workhouse and he said there but for the
- 10:34grace of God go I and that is sort of
- 10:38the idea behind uh John
- 10:41haran uh and rs's argument for
- 10:44redistribution so you read the piece by
- 10:45John har this idea I've learned recently
- 10:48actually shows up even earlier in a
- 10:51paper by William vicory who won the
- 10:53Nobel prize in economics um and they
- 10:57gave sort of a Libertarian or
- 10:59choice-based approach to why we should
- 11:02have uh uh
- 11:05redistribution and can anyone tell me
- 11:08what what the basic idea of that is yeah
- 11:09Adam well um pretty much uh because
- 11:12people are too young in that situation
- 11:16to like make a decision about like
- 11:17insurance but because people are usually
- 11:20risk averse they would choose in that
- 11:22situation to lower their income in like
- 11:25the wealthy State and raise it in the
- 11:27poor State as a form of insurance so the
- 11:29government should do you do that
- 11:32redistribution because they obviously
- 11:34can't yeah so the idea is you know
- 11:36people almost always seek re uh
- 11:39insurance against bad things that might
- 11:41happen to them major risks in their life
- 11:43like medical insurance auto insurance
- 11:45Etc and the reason is because money is
- 11:47worth more to you when you have a lot of
- 11:49it than when you don't have as much of
- 11:51it and you know one of the biggest risks
- 11:54you face in life is what position you're
- 11:56going to end up in are you going to be a
- 11:57brilliant person who makes a lot of
- 11:59money money or you going to be a um poor
- 12:02person who makes a lot less money right
- 12:04which parents will you have will you
- 12:05have good parents or will you have
- 12:06crappy parents who don't take good care
- 12:09of you um what country or town are you
- 12:12born into Etc and people can't buy
- 12:15insurance against these things because
- 12:16they're too young or not even born yet
- 12:19and therefore the government should act
- 12:20as an insurance agent CH giving people
- 12:23the insurance that they would have
- 12:25chosen to get had they been able to
- 12:27choose to do so um and that's exactly
- 12:30what redistributive spending does so um
- 12:34this Advocates the idea that we should
- 12:36implement the policy that people would
- 12:38have chosen behind the veil of ignorance
- 12:40about who they are within
- 12:43Society um another way of putting it is
- 12:47Adam Smith so rather than the veil of
- 12:50ignorance he said imagine you were an
- 12:51impartial Outsider looking at people
- 12:54what would you think of as the
- 12:57distribution that you would you would
- 12:58choose yeah can so on about the John R
- 13:01said about this the here whole thing of
- 13:04the max Min principle which is Rel
- 13:06that's an extreme version of this and I
- 13:09think it's not a very plausible version
- 13:10of this or very consistent with his own
- 13:13logic because behind the veil of
- 13:14ignorance why would people suddenly have
- 13:16this Max Min uh preference rather than
- 13:19the risk preferences we see them
- 13:21actually having in the world which are
- 13:23not completely maxmen yeah that's
- 13:25basically exactly what I was ask about
- 13:27why yeah so I I I'm not I don't find
- 13:29rs's version of this very compelling I
- 13:32find the vicory and harani versions much
- 13:34more compelling yeah my um would this uh
- 13:38leg justification have like in itself
- 13:40moral hazard problems well but the thing
- 13:43is we didn't say that that necessarily
- 13:45means that you should redistribute
- 13:48everything because there might be
- 13:50consequences if I redistribute that I'll
- 13:52work less hard that's the reason why we
- 13:54don't give perfect Insurance to people
- 13:56because we want to retain some incentive
- 13:58that theyy to avoid the bad events right
- 14:02the idea is we wouldn't just like
- 14:03perfectly yeah and that's what the rest
- 14:05of the class is going to be about is the
- 14:06tradeoff between Insurance versus
- 14:08incentives
- 14:10okay um yeah that's up people who are
- 14:14highly
- 14:15talented like before like even before
- 14:17the veil of even with the veil of
- 14:19ignorance and even um like before
- 14:22knowing their position in life if
- 14:23they're like inly talented say that
- 14:26there is well but maybe their talent you
- 14:28can step back to a step before they know
- 14:30what their talent is that's sort of the
- 14:32idea I mean I don't know if you think
- 14:34you can step back to such a state and in
- 14:36fact that's like a big debate uh whether
- 14:38like there are things which even behind
- 14:40the veil of ignorance you already know
- 14:41about yourself but you know because I
- 14:44mean in no way that's like the classic
- 14:46argument against fre distribution right
- 14:48because some people like some I don't
- 14:51necessarily believe this but some people
- 14:52believe you know people who are inly
- 14:54talented the called and so if they're
- 14:57yeah so I mean if you basically believe
- 14:58that there are certain things like that
- 15:00it's just that certain types of people
- 15:02have more than other types of people
- 15:04because like say even behind there's no
- 15:07situation in which they didn't know that
- 15:10Noble sess that they had right and in
- 15:12some sense that's like the Protestant
- 15:15idea as well right it's the idea that
- 15:16like certain people are sort of chosen
- 15:18by God to be more talented so if you
- 15:21believe that then you wouldn't want this
- 15:23and in fact you know I think a really
- 15:25interesting research program that hasn't
- 15:27really been worked out in economics is
- 15:30like what would optimal taxes be in a
- 15:32world where there's some properties that
- 15:34we don't want to redistribute and others
- 15:36that we do so like for example when when
- 15:39like there's a ugly person we don't
- 15:41usually say oh it's so unlucky for them
- 15:44that they were ugly right whereas when
- 15:46there's a beautiful person that gets hit
- 15:48by a car and now is ugly we say it was
- 15:50so unlucky that such a beautiful person
- 15:51ended up ugly right so people might
- 15:54approach these some things is more like
- 15:56about luck and some things more about
- 15:58what you Des erve or what you earned
- 16:00Yeah Austin not strictly do any like
- 16:03political science research into the
- 16:05decline of religion Europe trying to
- 16:06connect that to the rise of the
- 16:08distribution so I feel like that yes
- 16:10there definitely has been I don't know
- 16:11it that well but I could definitely
- 16:13direct you to somebody who would know it
- 16:14I have a friend who like knows the
- 16:15redistributive literature like better
- 16:17than anybody in political science so um
- 16:21yeah right um this is like still like
- 16:24ultimately like a philosophical sort of
- 16:26judgment right yeah I mean lots of
- 16:29things that we build our theories up
- 16:30from our philosophical
- 16:32judgments pretty much everything is
- 16:34because in the
- 16:36end you can only deductively bring
- 16:39things back to some fundamental
- 16:41principles that you just have to accept
- 16:42on faith
- 16:44so um okay so this perspective would say
- 16:48that we should try to maximize average
- 16:50utility and that's called
- 16:53utilitarianism uh Jeremy benam uh
- 16:56described it as trying to create the
- 16:57greatest good for the greatest number of
- 17:00people um and usually the way that we
- 17:03model this is that people have some
- 17:05utility that depend on income plus some
- 17:07value that they get from everything else
- 17:11like Leisure their identity enjoyable
- 17:13work
- 17:14etc so for utilitarian social welfare is
- 17:19the sum of all these individual welfares
- 17:22and people are waited equally because
- 17:24you don't know uh which individual
- 17:26you're going to be you're equally likely
- 17:27to be any of them so from this
- 17:29perspective inequality is just another
- 17:31form of inefficiency it's an
- 17:33inefficiency from the failure to provide
- 17:35Insurance um because the rich don't
- 17:37value money as much as the poor do and
- 17:40the reason is risk aversion and that's
- 17:42what we're going to go through now yeah
- 17:44Tanner in that equation what is the uh F
- 17:47of little i what does that function mean
- 17:48that's the number of people with that
- 17:51income I yeah EV should U should U of I
- 17:55plus v of X be in parentheses
- 18:00yeah yeah that's right I mean I yeah
- 18:04exactly uh yeah Adam um so in this
- 18:08equation like then um redistribution
- 18:11isn't solely like monetary based like
- 18:13someone finds work more enjoyable then
- 18:15they might have like we distribute less
- 18:17income to them they get utility from
- 18:20other areas
- 18:22or yeah so that's actually a really good
- 18:24question so um this is really assuming
- 18:27that everyone has the same utility
- 18:28function over
- 18:30income and if that's true then this is
- 18:32going to be the right formulation but
- 18:34we'll talk a little bit I think at the
- 18:35end of the class about a model where
- 18:37people could vary both in terms of how
- 18:40much they like
- 18:41money versus other things and how
- 18:45talented they are right and depending on
- 18:50whether you think you should
- 18:51redistribute that or how you should
- 18:52think you should redistribute that that
- 18:54could affect so a lot of people think
- 18:56that there's like a basic principle that
- 18:58we should redistribute differences in
- 19:00ability but we shouldn't redistribute
- 19:02the fact that like one person likes to
- 19:04work harder than another person does or
- 19:06like cares more about money than another
- 19:08person does so yeah Tanner doesn't this
- 19:11assume that utility is Cardinal not
- 19:13ordinal well but but I think that people
- 19:17view it that way because they have to
- 19:19make like when people buy insurance
- 19:21they're saying that money is worth more
- 19:23to them when they're poor than when
- 19:24they're rich right and if you want to
- 19:27say like what would be my value for
- 19:28being various different people in the
- 19:30world you have to have some Cardinal
- 19:32isation of your utility for that so like
- 19:35when you have when you think about
- 19:36Choice over uncertainty that creates
- 19:38that has to create a calization of
- 19:42utility okay so utility is assumed to be
- 19:45concave in income and the idea behind
- 19:48this is risk aversion roughly you start
- 19:51as you get more money running out of
- 19:53good uses of that money so like when
- 19:55you're poor money is great because it
- 19:57allows you to buy like a house that
- 19:58doesn't fall down and food that you need
- 20:01and health basic health care as you
- 20:02start get getting richer what do you do
- 20:04with all the money I guess you can have
- 20:05like you know Justin Bieber come and
- 20:07sing for your daughter whatever but it
- 20:10maybe that's not as valuable per dollar
- 20:12as the other things right
- 20:15um okay now if you don't believe in risk
- 20:18aversion uh let let me give you a little
- 20:21example that hopefully will persuade you
- 20:23uh to believe in risk aversion okay so
- 20:26imagine that we flip a coin
- 20:29um and you get $2 if it comes up heads
- 20:32and if it comes up sorry if it comes up
- 20:34tails and if it comes up heads you flip
- 20:36it again if if it comes up tails you get
- 20:39$4 and if it comes up heads you flip it
- 20:41again etc etc etc doubling each time
- 20:46right so uh Austin how much would you be
- 20:50willing to pay in order for me to offer
- 20:52you this bet if you flip a coin can you
- 20:55explain that here okay I flip a coin if
- 20:58it comes up tails you get $2 if it comes
- 21:00up heads you get to flip again if it
- 21:03comes up tails you get $4 if it comes up
- 21:05heads you flip it again if it comes up
- 21:08taals you get 16 $8 yeah Etc let's see
- 21:11here it would be the value would be the
- 21:14sum
- 21:16of 2 n * 1 2
- 21:21N so
- 21:24$2 is that the sum of hold on 2 to the n
- 21:281 what's the sum from I = 1 to Infinity
- 21:33of 2 the I * 1 2 the i 2
- 21:38I what is 2 the I over 1 * 1 over 2 the
- 21:44i 2 I over
- 21:472 yeah what's that one one so it's the
- 21:51sum of one + 1 + 1 + 1 + 1 + 1 + 1
- 21:56infinitely so how much would you you
- 21:59personally be willing to pay in order to
- 22:01get me to do
- 22:03this you know I feel like there's some
- 22:08Inc yeah maybe yeah what would you what
- 22:13would you be willing to pay for this
- 22:14I'll put in 100 bucks 100 bucks is
- 22:17anyone here willing to pay more than 100
- 22:19bucks raise your
- 22:21hand um uh is anyone here willing to pay
- 22:26more than 200 bucks more than than a
- 22:28th000 bucks more than 10,000 bucks no I
- 22:33didn't think so okay uh so clearly you
- 22:35guys are not okay how much would a risk
- 22:38neutral person be willing to pay for
- 22:40this uh yes so well like
- 22:44an expected the
- 22:47expected exactly is
- 22:50this what no sorry you going say I was
- 22:53just thinking this kind of reminds me of
- 22:54like a physics question where like
- 22:56theoretically the tales are infinite but
- 22:58just because of like quantization is
- 22:59practic it seems like you got a similar
- 23:02thing no but I mean I could give you
- 23:03things that like didn't literally sum to
- 23:05an infinite amount but sub to something
- 23:07enormous and you still wouldn't be
- 23:08willing to pay you know a very large
- 23:11amount for it yeah M so every time it it
- 23:15lands heads you get to flip again yeah
- 23:17so why wouldn't anybody pay $10,000 for
- 23:20this because you keep getting larger
- 23:21payouts and then you know that it's
- 23:23going to come up taals like infly many
- 23:25times right if you but you only get to
- 23:27do it once oh
- 23:29okay so yeah yeah re so I mean in this
- 23:34it's possible you flip it once and get
- 23:36once you paid $10,000 for it you flip at
- 23:38ones it lands tails and you get two both
- 23:41yeah okay so you could
- 23:43lose
- 23:489,000 okay so apparently you guys are
- 23:50not risk
- 23:51neutral right and it's hard to imagine
- 23:54any reasonable person paying all that
- 23:56much for this thing right and and so
- 23:58therefore it seems reasonable to think
- 24:01that people are risk averse so imagine
- 24:03that people had log
- 24:05utility you could just go through and
- 24:07compute how much people are willing to
- 24:09pay for this uh starting from zero they
- 24:12should be willing to pay the log of all
- 24:13these things which is rather than
- 24:16doubling it it's only adding a constant
- 24:18so it would die off exponentially and
- 24:21you would be willing to pay very little
- 24:22for this yeah uh doesn't it depend on
- 24:25how much income you're currently at
- 24:28depend
- 24:29it does yeah so the more income you're
- 24:31currently at the more you should be
- 24:32willing to pay for this for
- 24:35sure um yeah so uh like even a gambler
- 24:41or like somebody who's considered
- 24:45um risk loving yeah they wouldn't like
- 24:49CU they're not really risk loving over
- 24:51the full range that's the point right
- 24:53like they might be risk lugging for a
- 24:55little bit but they wouldn't really take
- 24:57this big of a risk you know so they're
- 25:00like Risk loving for certain levels
- 25:03maybe I don't even think they're really
- 25:04risk loving I think that they like they
- 25:06they just are over optimistic about
- 25:08their chances of winning I mean that's
- 25:09my basic view yeah Tanner I actually
- 25:12want a guy who trades through for J
- 25:14Morgan say that he would want to bet on
- 25:15Cor if he could like in his job well of
- 25:19course that's true because he's betting
- 25:21with the government's
- 25:22money person like he loves to gamble
- 25:25that's people do I don't believe it
- 25:27maybe it's because he's used to
- 25:28something with a much lower expect no I
- 25:31I think that he's saying that like with
- 25:32the company's money he would want to do
- 25:34that because then in the end like you
- 25:37know if if it loses a lot of money the
- 25:39worst thing that happens is he get fired
- 25:41and if he makes a lot of money he gets
- 25:4230% of that he was talking about this in
- 25:44conjunction with his like gambling habit
- 25:46so like his personal I think he would do
- 25:48it for both time both but I would
- 25:49certainly wouldn't do it for like this
- 25:52much you know no but for some for some
- 25:54measure he was risk buing yeah maybe
- 25:57yeah I don't isn't it possible to be
- 25:59like purely risk averse and be a gambler
- 26:02you just also derive like utility from
- 26:04like the adrenaline or whatever maybe
- 26:06yeah I mean I think that it's mostly
- 26:08that people like misestimate the chance
- 26:11that they are going to win or they trick
- 26:15themselves into the kingdom yeah okay so
- 26:20um risk
- 26:21aversion um alone uh therefore gives
- 26:25some motive for redistribution
- 26:28but the if we're more specific about the
- 26:30form of utility we can get a much more
- 26:32useful uh
- 26:34measure um and luckily there's some
- 26:37pretty powerful evidence about this the
- 26:39same way there was for Zip's law in
- 26:41partic in particular a lot of uh
- 26:44evidence points us to The View that
- 26:45people's utility is roughly logarithmic
- 26:47which is kind of amazing because this
- 26:49form for utility was first proposed in
- 26:51the 17th century and basically nothing
- 26:53we've done since then has convinced us
- 26:55that there's any better approximation to
- 26:57people's utility since then um and this
- 27:00is super intuitive to think about it
- 27:02basically says the value of a certain
- 27:04percentage increase in your income is
- 27:06constant no matter what income you're at
- 27:07so like d like someone is just as happy
- 27:10to move from $50,000 of income to
- 27:12100,000 as from 100,000 to2 200,000 as
- 27:15from 200,000 to 400,000 Etc it's
- 27:18mathematically very convenient and has a
- 27:20lot of empirical support so my favorite
- 27:23support for this comes from uh paper by
- 27:25uh Dan sax and co-authors and they
- 27:28studied subjective wellbeing measures
- 27:31these are when we run a survey and we
- 27:33ask people on a ladder of life from zero
- 27:36being like the worst life you can
- 27:38imagine living to 10 being the best life
- 27:40you can imagine living where would you
- 27:42put yourself and let's let H be the
- 27:45number that people report and I be the
- 27:47income that they earn yeah philli um
- 27:50don't if you survey someone with
- 27:52sufficiently high income uh might you
- 27:55have a problem fitting this to a log
- 27:57data because if it was log outa they
- 27:59would want to report above a 10 but they
- 28:02can't because it's yeah I mean I don't
- 28:04think that you in a random sample very
- 28:07often get such people that's true
- 28:09because like yeah there's not that many
- 28:13people who are 10 log points higher than
- 28:17like a average person in the
- 28:19population it's it has to be even more
- 28:21than 10 log points here because the
- 28:23coefficient turns out to be33 so they'd
- 28:26have to be 30 log points out
- 28:30so that's a
- 28:31lot uh let me figure out exactly what
- 28:34that
- 28:41is but still isn't that kind of like
- 28:44somewhat fla
- 28:46measurement well hold on one second let
- 28:48me just figure this out e to the 30
- 28:52times let's say that someone who's at
- 28:54one is at one right so
- 28:59yeah it can't even tell me what that is
- 29:00it's some like ungodly large number
- 29:03about 10 to the it's on the order of
- 29:05about 10
- 29:1015 because e is approximately theare of
- 29:1310 so it's something like that yeah
- 29:17that's like that's like trillions of
- 29:20trillions of dollars right
- 29:23so um okay 1.07 * 10 the
- 29:2913 what's 10 the 13th so we take three
- 29:31off of that to get thousand three off of
- 29:33that nine off of that gets us to
- 29:36billions right take another three off
- 29:39that gets us to trillions so that's like
- 29:42hund tens or hundreds of trillions of
- 29:44dollars or something so yeah you're not
- 29:45going to get someone like that in exle
- 29:48okay uh so this is what they find fits
- 29:51incredibly well so this if you run this
- 29:55regression you get H is equal to35 * the
- 29:58log of income plus Epsilon so just to
- 30:00show you how powerful this is here are
- 30:03200 countries and each one of these
- 30:05countries they ran the regression within
- 30:07the country of income and here are the
- 30:10regression coefficients like given by
- 30:13these lines
- 30:14right and here is the cross country
- 30:16regression so you see these things are
- 30:18like all pretty much the same and
- 30:20they're all pretty much parallel to the
- 30:21cross country relationship so I think
- 30:24that shows pretty compelling evidence
- 30:26that um BAS basically logiic income does
- 30:30a good job of explaining uh yeah right
- 30:33but um doesn't like sort of measure of
- 30:37your wellbeing like run the same
- 30:39problems like a con valuation surve you
- 30:41would think so wouldn't
- 30:44you but I think the data speaks louder
- 30:47than the theory I mean like the fact
- 30:50that people that this does such a good
- 30:53job explaining the data I think answers
- 30:56a lot of the objections that you could
- 30:58happen too but what if like everybody
- 31:00has the same sort of bies like but then
- 31:03why does it line up so perfectly with
- 31:05the logarithm of their
- 31:11income I mean it's just like you know
- 31:13yeah I agree there th This Is Right
- 31:15without having any right to be right but
- 31:17still it is seems to be right yeah
- 31:20Austin what about like relative income
- 31:22effects exactly that's what you would
- 31:23think if it was relative income effects
- 31:25then you would expect the relationship
- 31:27cross countries to be much flatter than
- 31:28the Rel relationship within countries
- 31:31because the rich countries would
- 31:32everyone would have a higher Baseline
- 31:34and you wouldn't expect them to be any
- 31:35happier but that's not what
- 31:38happens yeah um is there any data on
- 31:42risk preferences that also support yes
- 31:45there's like a ton of data there's a
- 31:47nice paper by Raj cheddy that looks at
- 31:49like 10 different ways of measuring risk
- 31:51aversion they all line up really well
- 31:52with logarithmic
- 31:55utility okay so all the things together
- 31:58mean that I think especially given that
- 32:00it's so convenient we can just go run
- 32:02with logarithmic utility okay so
- 32:05designing an optimal tax system involves
- 32:07a wide range of issues you have to
- 32:09decide what you're going to tax is it
- 32:10going to be income consumption Capital
- 32:13how is the um how do we redistribute the
- 32:16money that's
- 32:17collected um what deductions do we give
- 32:21people and what is the base for the
- 32:23taxes uh do we give just uniform
- 32:26deductions or do we give them targeted
- 32:28to particular groups for doing
- 32:29particular things do we have inheritance
- 32:32taxes you know how do we tax different
- 32:34Generations how many brackets do we have
- 32:38and where at what income thresholds what
- 32:40rate do we have over each of these
- 32:42brackets we have to make decisions about
- 32:44the administrative process what
- 32:46government programs to spend the money
- 32:48on to give subsidies maybe over some
- 32:51range just for people getting into the
- 32:53workforce at all so these are really
- 32:55important issues but today we're only
- 32:57going to focus on two of them that have
- 32:59been sort of very important to economics
- 33:01as well as in the news one is how high
- 33:05should overall tax rates be and how flat
- 33:08or Progressive should things be on the
- 33:10Super Rich should we have like a higher
- 33:12rate on the Super Rich than on the rest
- 33:13of the population or not okay
- 33:16so you know if we if the poor value uh
- 33:22money more than the rich do why should
- 33:24we not just redistribute everything
- 33:26until we have perfect to Quality can
- 33:29someone uh yeah Julian uh because then
- 33:32nobody would have any incentive to work
- 33:34CU they can do not work and then they're
- 33:36still the same amount of money exactly
- 33:38because if you tax people more they have
- 33:40less marginal incentive to work so in
- 33:42particular Beyond some point more taxes
- 33:44are counterproductive because you'll
- 33:46actually raise less total revenue and
- 33:48this is uh called the equity efficiency
- 33:50tradeoff or the insurance incentives
- 33:53trade-off and the basic goal in this
- 33:55problem is to maximize average utility
- 33:58given that we can only use let's say a
- 34:00simple instrument we have like a linear
- 34:03tax on everyone's income and then we
- 34:06redistribute that back to people and
- 34:08then maybe we have the search charge on
- 34:09the rich and that raising taxes causes
- 34:12less work because people substitute down
- 34:15to doing less work and all revenue is
- 34:17given back lump sum to everyone now to
- 34:20keep things simple we're going to ignore
- 34:22income effects because
- 34:25um a lot of reseearch has shown that
- 34:28those aren't all that important to
- 34:29determining this problem we can
- 34:31incorporate them of course but the
- 34:33formulas get a uh
- 34:36Messier uh and it doesn't make much of a
- 34:38difference right so in that case all the
- 34:40reduction comes from What's called the
- 34:41labor Supply
- 34:42elasticity which is the percent Fallen
- 34:45work when your wages Fall by a percent
- 34:48and let's say that people who are
- 34:50currently earning income I have an
- 34:53average labor Supply elasticity of
- 34:55Epsilon bar
- 34:58okay now people's income after we have
- 35:01taxes and transfers are going to be
- 35:04they'll get one minus the tax rate times
- 35:07their income plus the tax rate times the
- 35:09average income because we're going to
- 35:11redistribute that average income that we
- 35:13tax away back to people lump some okay
- 35:17so um the post tax wage that people earn
- 35:22is one minus the tax rate times their
- 35:24wage
- 35:25right and so if we raise taxes by uh one
- 35:31unit how much is that going to cause
- 35:35people's earnings to Fall by if they
- 35:37have an elasticity of Epsilon Tanner can
- 35:40you derive
- 35:42that Bo yeah
- 35:44sure so the remember that the labor
- 35:47Supply elasticity was the
- 35:50elasticity of um like how much your
- 35:54income changed when your wage Changed by
- 35:571%
- 35:59%
- 36:25yep the post test which is that so you
- 36:28want to find the change in that as the
- 36:30tax changes yes exactly no the change
- 36:33the change in the total amount of income
- 36:35you're going to earn we also have to do
- 36:37that yeah so we'll have to figure out
- 36:39how much this changes how much the
- 36:40elasticity Chang yeah and then the
- 36:41elasticity will do the rest for us okay
- 37:14[Applause]
- 37:22so tea only shows up once in there right
- 37:24yeah so I'm
- 37:34yeah that's it and then you need to
- 37:37multiply so to get that turn that into
- 37:39an elas uh to to okay so then the
- 37:44elasticity says uh if you take that
- 37:48number uh and you divide it by the
- 37:53current uh wage which is W * 1 -
- 37:59T then you can multiply it by the
- 38:05elasticity and and then yeah and that
- 38:09should give you um how
- 38:13much uh how much the income by what uh
- 38:18percentage the amount that people work
- 38:20changes so it's just this
- 38:25yeah exactly
- 38:31so when we raise um the income when we
- 38:36raise
- 38:37taxes they'll uh the amount that people
- 38:40work will fall by the labor Supply
- 38:42elasticity averaged at that income tax
- 38:45level times 1 minus uh the T divided by
- 38:491 minus the tax rate okay and this is
- 38:54the income weighted average elasticity
- 38:57of Labor
- 38:59Supply uh and imagine that there is a
- 39:02density of people over different incomes
- 39:05of f ofi so like that's the number of
- 39:07people earning a given income that's
- 39:08what we were talking about before again
- 39:11we're going to ignore income effects so
- 39:14then total welfare remember is going to
- 39:17be the integral over the incomes of the
- 39:20logarithm of the income right now each
- 39:24individual by the envelope theorem the
- 39:27the only cost to them of taxing them is
- 39:30the amount of money that they
- 39:32lose times whatever their marginal
- 39:34valuation of that money is because any
- 39:37amount that they go into working uh into
- 39:41reducing the amount of work right
- 39:43they're choosing the optimal amount of
- 39:45work given um given uh the tax rate
- 39:49right so we can now take the derivative
- 39:52of this and what do we
- 39:55get well uh derivative of the logarithm
- 39:59is one over the inside right times the
- 40:03number of people at that income and then
- 40:05what happens to uh what happens to my
- 40:09income by the envelope theorem I can
- 40:11hold fixed but the average income is
- 40:14going to change because people other
- 40:15people are going to work less when we
- 40:17tax more right and what's that going to
- 40:21change by well I'm going to raise this
- 40:24by one because I'm collecting more taxes
- 40:29and then I'm going to reduce it by um
- 40:35the amount of
- 40:36taxes times however much the income
- 40:39changes which is the elasticity Time 1
- 40:42minus the tax rate and then these people
- 40:45also lose directly by the envelope
- 40:47theorem their
- 40:51income and that gives us this formula
- 40:55here which is 1
- 40:59minus the tax rate times the
- 41:02elasticity ID 1us the tax rate times the
- 41:06average income and the average welfare
- 41:08weight that's one o this is the amount
- 41:11of like value that the person gets from
- 41:13an additional dollar that's one over
- 41:15their post tax
- 41:17income minus the average value of the
- 41:20product of income and the welfare weight
- 41:24right now I'm going to define a variable
- 41:28Sigma which is going to be the negative
- 41:31co-variance of income divided by average
- 41:34income with welfare weight divided by
- 41:36average welfare weight now why should
- 41:38this be a negative number well the
- 41:41Richer someone is the less they value an
- 41:43additional dollar and this is sort of a
- 41:45measure of
- 41:47inequality why because if everyone had
- 41:50the same income there would be no
- 41:51covariance there right the more
- 41:54covariance there is there the more
- 41:56inequality there
- 41:58right the more that people's income are
- 42:01moving around and therefore the more
- 42:03their welfare rates are moving around
- 42:04now obviously if we have higher taxes
- 42:07that's reducing inequality and leading
- 42:09to less variation in the welfare weights
- 42:10and therefore less Co negative
- 42:12co-variance with income yes you well can
- 42:15you explain why um you Define welfare
- 42:16weight as one over the because that's
- 42:19the marginal utility that someone gets
- 42:21from an additional unit of uh dollar and
- 42:24that's therefore the weight the society
- 42:25should place on them getting an addition
- 42:27so if everybody has the same log
- 42:29function then isn't the coherence always
- 42:31going to
- 42:33be the same um no because it depends on
- 42:36the degree of inequality right because
- 42:38the thing is that um if someone has
- 42:40higher income then their weight is going
- 42:42to be lower because they value income
- 42:45they value money less right and if you
- 42:47make things more equal by having higher
- 42:49tax rates then these are going to be
- 42:50closer to being equal and there will be
- 42:52less co-variance
- 42:54there okay so
- 43:00um optimization
- 43:03then is going to
- 43:05be that uh
- 43:091us T average elasticity over 1 minus t
- 43:13is equal to this
- 43:16co-variance and so we can just solve out
- 43:19that the optimal tax rate is going to be
- 43:21equal to this measure of inequality
- 43:24which depends on the tax rate divided by
- 43:26the average elasticity times this
- 43:28measure of inequality which depends on
- 43:30the tax
- 43:31rate okay so the tax is going to be
- 43:37increasing in Sigma and decreasing in
- 43:41epsilon and how does that uh capture the
- 43:44trade-off between equity and efficiency
- 43:46can someone explain that yeah joh this
- 43:49it's increasing that means the equity is
- 43:53increasing along the perance rate sorry
- 43:56say that again it's becom more evitable
- 43:58because the sigma is
- 44:00increasing well so Sigma is a measure of
- 44:03inequality right sorry so it's becom
- 44:04more inequitable uhhuh so but okay so
- 44:09what this is saying is that the more the
- 44:11bigger Sigma is the bigger the optimal
- 44:13tax rate should be and the bigger
- 44:15Epsilon is the lower the optimal tax
- 44:18rate should be so how does that reflect
- 44:20this logic we were discussing before
- 44:23that Julian was pointing out of the
- 44:24trade-off between trying to get greater
- 44:26equal quity and greater uh efficiency so
- 44:31if Sigma is greater that means the tax
- 44:34be greater at the same time that because
- 44:36why why because why should it be greater
- 44:40because well no I I agree but but why
- 44:43why intuitively how does that correspond
- 44:45to the intuitive logic we were talking
- 44:46about before about the trade-off between
- 44:48equality and
- 44:52efficiency anybody else uh yep um bar uh
- 44:59so uh as the elasticity increases the
- 45:02tax rate should be lower because um if
- 45:06the elasticity is higher that means
- 45:08people are more responsive to a higher
- 45:10tax rate will work less yes and
- 45:12therefore there's more efficiency cost
- 45:15because of the moral hazard issues right
- 45:17yeah and and what about Sigma why when
- 45:19that's higher should there be higher T
- 45:22um because in that case if Sig higher is
- 45:25more inquality yeah so a higher tax is
- 45:28necessary
- 45:29to distribute that because poor value
- 45:32exactly
- 45:35exactly
- 45:37um okay so this is a simple
- 45:39formalization of the equity efficiency
- 45:41tradeoff and if Sigma is getting very
- 45:44very large except near T equals 1 then
- 45:48we're going to want tax rate of one or
- 45:51if the elasticity goes to zero we're
- 45:52going to want a tax rate of one and vice
- 45:54versa so the more inequality there is
- 45:57and the less elasticity is the higher
- 45:59the optimal tax rate is okay so that
- 46:03average tax rate covers um like the tax
- 46:08that is going to be faced by most
- 46:09Americans or most people in a given
- 46:12country but Obama has now not that
- 46:15recently caused uh called for a sear
- 46:18charge on the super rich and when taxing
- 46:23the super rich the amount of money that
- 46:25they lose as a result of that tax
- 46:27doesn't matter that much to see that
- 46:29notice that um one over a million dollar
- 46:34is only about 1 12th of one over the
- 46:37median income in the United States and
- 46:39so therefore like the marginal value of
- 46:41an additional uh dollar for the rich
- 46:44people is hardly anything compared to
- 46:46for a typical person right and so a
- 46:49simple way to think about this is that
- 46:50we should just try to maximize revenues
- 46:54um on on the wealthy right so imagine
- 46:58that we had a tax rate for those earning
- 47:01over a million dollar uh which we called
- 47:05uh T sub 10 6 and let's let uh I bar sub
- 47:1010 the 6 be the average income of those
- 47:12who are earning over a million dollar
- 47:15right now if we raise this tax rate
- 47:18that's going to cause uh two effects can
- 47:20someone describe to me what those two
- 47:22effects will
- 47:23be uh yeah um you're going to have a
- 47:27higher a tax take mechanically cuz we
- 47:31are raising uh we're taxing more heavily
- 47:34but they are going to respond by working
- 47:36less and that's going to have a opposite
- 47:39effect exactly so there's a mechanical
- 47:42increase in the revenue that we earn
- 47:44which is that for every dollar that
- 47:46these people earn over a million dollars
- 47:48we'll get one more Dollar in tax revenue
- 47:51but also there will be for everyone
- 47:53earning an income Above This their
- 47:55incomes will fall by this this amount
- 47:57which will reduce the tax taxes that we
- 47:59get by this amount yeah how is this so
- 48:03when you say that increase revenue from
- 48:05I by IUS 106 does that mean you're
- 48:07taking every no it's only we don't get
- 48:10money that's below a million these
- 48:13people earn right because the tax ratees
- 48:15only charged above a million do so it's
- 48:18a marginal tax rate above a million doar
- 48:20okay oh so you're just saying that we
- 48:22get T * IUS well we get we're changing T
- 48:26right so we get for every unit change in
- 48:28t This Much from each
- 48:30person yeah
- 48:34re was what T der that's the percent
- 48:37change yeah
- 48:39exactly anybody
- 48:42else okay so the total effect on revenue
- 48:47is therefore we get i - 10 6 * 1 minus
- 48:52this
- 48:53reduction uh in in taxes is from the
- 48:58effect we talked about and the optimal
- 49:00tax is going to equate this to zero on
- 49:02average for people above a million
- 49:05dollar and this was the formula derived
- 49:08by Emanuel Siz in 2001 so if we take
- 49:11averages we just can put bars over all
- 49:13this stuff right where again e bar sub
- 49:1710 6 is the a average income weighted
- 49:20elasticity of people earning an income
- 49:22above uh a million dollar and I bar the
- 49:266 again is the average income of those
- 49:28who are earning over a
- 49:30million okay so now let's define Alpha
- 49:33to be I bar sub 10 6 divided I bar sub
- 49:3810 6 minus 10 6 so that's the average
- 49:41income that people earning above a
- 49:42million are doing divided by on average
- 49:45how much more than a million dollar are
- 49:47they
- 49:47earning okay so by the same logic as
- 49:51before um what are we going to uh get as
- 49:55the optimal tax formula Adam you could
- 49:57you derive that on board yeah
- 50:13sure so you'd set that equal to zero
- 50:16yeah exactly and then try to use that
- 50:19Alpha thing that
- 50:20I find
- 50:28o
- 51:14C
- 51:32[Applause]
- 51:38[Applause]
- 51:48yes so you've got to get all the t's on
- 51:50one side so you can divide through and
- 51:52solve for it right yeah so I just divide
- 51:54by oh you've got another one on that
- 51:57right so I actually don't think you did
- 51:59a very good job isolating it there yeah
- 52:02forgot about that too uh
- 52:19so how about isolating the left hand
- 52:22side
- 52:23thing this over here yeah
- 52:27and so subtracting one from subtract one
- 52:29from both sides
- 52:50yeah okay now before you do anything
- 52:53else try turning the right hand side
- 52:54into something that's related to
- 52:55something I have on the
- 52:57board
- 52:59um
- 53:01so this
- 53:20equals so that would be one over Alpha
- 53:23good okay so try putting that in that's
- 53:25going to make your life easier
- 53:43um now you need to isolate T sub 10 6
- 53:59multiply both sides by the denominator
- 54:01right
- 54:17yeah okay
- 54:32+ one
- 54:36yeah what that uh okay try doing it this
- 54:40way try just bringing the other t to the
- 54:43other side of the equation so you'll
- 54:45have t * 10 6 * EP Epsilon + 1 over
- 54:50Alpha is equal to 1
- 54:52Alpha what you say again try bringing
- 54:55the T term t Alpha to that side of the
- 54:57equation and factoring out the T the sub
- 55:0110
- 55:026 bring this one to the side and then
- 55:04factor out the T sub 6 on the
- 55:13left no no don't divide don't divide
- 55:17okay just just bring this over and then
- 55:20factor of T so you can then divide so
- 55:24does setal zer this saying subtract
- 55:41this okay
- 55:54plus off
- 55:56and now you got it
- 56:14yeah okay nicely done Adam so that's
- 56:18what Adam got 1 over Alpha + 1 Alpha
- 56:21plus e sub 10 6 now remember that Alpha
- 56:26uh what where do we use Alpha
- 56:28before well it turns out that this thing
- 56:33up here is equal exactly to the Proto
- 56:36coefficient of the upper tail of the
- 56:37income
- 56:39distribution
- 56:41um so uh what this says is that the
- 56:47lower is
- 56:48Alpha right the higher should be taxes
- 56:52and the higher is the elasticity the
- 56:54lower should be taxes right
- 56:57in
- 56:58particular if 1 over Alpha is greater
- 57:02than the our other measure of inequality
- 57:06then we're going to tend to make taxes
- 57:09more Progressive that is the rate at the
- 57:10top should be higher than it is
- 57:13throughout and it will tend to be more
- 57:16Progressive if the rich have lower
- 57:18elasticity than most Americans
- 57:20do
- 57:21right so those are the conditions under
- 57:24which things are progressive okay
- 57:26so to get a sense for uh Sigma let's
- 57:31first assume that the distribution of
- 57:33income is log
- 57:34logistic um that means that it takes
- 57:37this form turns out then that beta is
- 57:39equal to one over the Genny coefficient
- 57:42which is about 045 in the United States
- 57:44and the mean income turns out to be
- 57:47equal to this which uh mean income is
- 57:50about 46,000 in the US and that gives us
- 57:54that the alpha coefficient sorry this is
- 57:56a little bit confusing this is the alpha
- 57:57for the log logistic distribution not
- 57:59the alpha for the upper tail of the
- 58:01income distribution is uh that and so
- 58:05then you get that Sigma is a function of
- 58:07T looks approximately like this so um
- 58:13if uh we
- 58:16then uh plug that into our previous
- 58:19equation Sigma over the elasticity plus
- 58:22uh Sigma we get curves looking like this
- 58:26that determine what the optimal tax rate
- 58:28is so if the elasticity is .1 optimal
- 58:32taxes are about uh SE
- 58:3765% or so if elasticity is.3 optimal
- 58:41taxes are about um uh 40 uh 7% and as
- 58:48elasticity increases optimal taxes
- 58:51fall okay calcul yes well sorry so you
- 58:54used um Ed a measure of inequality and
- 58:57average income to determine like the
- 58:58spread of income ranges yeah but um how
- 59:01did you like how did you choose that
- 59:03this still be like the distri
- 59:05distribution function to be log logistic
- 59:07you mean or like why would it be log
- 59:09logistic well just because that seems to
- 59:11be good approximation if you look at
- 59:12more detailed data about the US income
- 59:14distribution the log logistic
- 59:16distribution over most of the range
- 59:17seems to be pretty good it's not good at
- 59:19the top part of the income distribution
- 59:21at
- 59:22all but um this is mostly like our
- 59:25average tax rate so it's mostly going to
- 59:27be dependent on the things like the
- 59:29Genny that determine the average income
- 59:31not uh income inequality over the main
- 59:34range not over the very top was like one
- 59:37of the reasons you chose it because it
- 59:38just includes the Gen coefficient was
- 59:40that yeah I mean you can also do that
- 59:42with log normal but it's a slightly more
- 59:44complicated transformation but yeah
- 59:47right sorry on that last slide like uh
- 59:50what do what does each line
- 59:54mean so each of these Cur curves
- 59:56represents Sigma of T divided by the
- 59:59elasticity plus Sigma of T okay which
- 1:00:02was what we said was the right hand side
- 1:00:04of the optimal tax formula so and the
- 1:00:07left hand side is the tax rate so we
- 1:00:08just intersect this with the 45° line to
- 1:00:10get the optimal
- 1:00:12taxes okay calculating Alpha is even
- 1:00:17easier so the upper part of the income
- 1:00:19distribution has a Proto tail which
- 1:00:21let's say is equal to 1.5 though it's
- 1:00:24somewhere between 1.5 and 3
- 1:00:27if you then just go through and
- 1:00:28calculate what I bar is under a Proto
- 1:00:32distribution uh you get that it's equal
- 1:00:34to 10
- 1:00:366 * Alpha over 1 + Alpha and so that
- 1:00:40gives you that I bar 10 6 over I 10 6 -
- 1:00:4310 6 is exactly equal to Alpha so I
- 1:00:46named it Alpha because it was the upper
- 1:00:48tail of a prto
- 1:00:51distribution prto distributions always
- 1:00:53have the property that if you take the
- 1:00:55average value of income above some level
- 1:00:58divided by that average value minus that
- 1:01:00level you always get a constant which is
- 1:01:02equal to Alpha okay so if you then plug
- 1:01:06into the formula with the elasticities
- 1:01:07of
- 1:01:080.13.5 and 1 you get optimal taxes of
- 1:01:1187. 6957 and4 as compared to Optimal
- 1:01:16taxes for the same elasticities of 6748
- 1:01:2038 and
- 1:01:2126 uh under for the main part of the
- 1:01:25income distribution
- 1:01:26now of course the elasticity is for
- 1:01:28these different groups is going to be
- 1:01:29crucial but this tends to lean us
- 1:01:31towards having Progressive taxes and the
- 1:01:33main reason is because inequality is so
- 1:01:35high at the top end of the income
- 1:01:36distribution if we hadn't been having
- 1:01:38this dramatic increase of inequality at
- 1:01:40the top end then we wouldn't have wanted
- 1:01:42to have more Progressive taxes so the
- 1:01:45reason why you tend to have this is
- 1:01:48because inequality has been growing more
- 1:01:50at the top end of the distribution than
- 1:01:52uh throughout the middle range of the
- 1:01:54jny coefficient
- 1:01:57okay now there yeah Adam I just a
- 1:02:00question so is this pretty much like
- 1:02:02with the look of the elasticity and the
- 1:02:03fact that this pretty much just like
- 1:02:05static view attack is like not the
- 1:02:06effect of like increase productivity
- 1:02:09over time well okay remember that when
- 1:02:12we talked about static models we can
- 1:02:14have short-run static models and long
- 1:02:16run static models so the issue is not
- 1:02:17really about whether it's static not
- 1:02:19it's about how longterm you're thinking
- 1:02:21about things and that's what I'm about
- 1:02:23to bring in so almost all the evidence
- 1:02:25that we have about the effects of taxes
- 1:02:28is based on short run changes right um
- 1:02:33and this can either bias things upward
- 1:02:37or downward so a really short run change
- 1:02:40might lead people to work less but they
- 1:02:42might just work more the next year or
- 1:02:43more importantly they might like
- 1:02:44manipulate their taxes to make it look
- 1:02:47like they had less income this year and
- 1:02:48then that it came in the next year right
- 1:02:50to take advantage of the lower taxes but
- 1:02:52on the other hand as you're pointing out
- 1:02:54at them there might be longer term
- 1:02:56things that higher taxes do for example
- 1:02:58it might change the types of careers
- 1:03:00people do it might change whether people
- 1:03:02get a good education in order to get a
- 1:03:05higher paying job it might change
- 1:03:07whether people go into the labor force
- 1:03:08at all until they get older it might
- 1:03:11change uh like the whole culture of a
- 1:03:13country that people are just like lazy
- 1:03:15in Europe because and everything thinks
- 1:03:19that's acceptable because taxes are
- 1:03:20lower right are higher right okay so
- 1:03:24these measures has shown that the labor
- 1:03:27Supply elasticity of the rich is very
- 1:03:30low but their taxable income elasticity
- 1:03:33that is the total amount that they're
- 1:03:35reporting earning e even though they
- 1:03:37don't work less when taxes rise at least
- 1:03:39in the short term they do report earning
- 1:03:42a lot uh less and uh why might that be
- 1:03:46the case uh is Kim here I don't think he
- 1:03:48is no um Can somebody else guess why
- 1:03:52that might be the case uh yeah myy uh
- 1:03:56like loopholes in the tax system
- 1:03:58basically yeah they can shift their
- 1:04:00income over time they can make it look
- 1:04:02like they earned
- 1:04:04income later right or they might just uh
- 1:04:09put more effort when taxes are higher
- 1:04:10into evading taxes that's another thing
- 1:04:13right yeah so could it also be that
- 1:04:16because they value income more in the
- 1:04:18present they just underreports that then
- 1:04:20when they're paying taxes on more in the
- 1:04:22future it's still discounted
- 1:04:26sorry say that again so if they
- 1:04:28underreport their income in the short
- 1:04:31run yeah it could just be because they
- 1:04:33value it more now so if they have to
- 1:04:34report it in the future even though
- 1:04:36they're paying taxes on on that what do
- 1:04:39you mean by value it more now in other
- 1:04:41words it's not discounted
- 1:04:43now yeah I mean but that's why they're
- 1:04:45substituting they're like making it look
- 1:04:47like they earned the income later in
- 1:04:49order to try to pay less taxes right
- 1:04:52yeah isn't that ask asking why
- 1:04:56well no but I mean of course the reason
- 1:04:58why they're doing that is to pay less
- 1:04:59taxes right um yeah so uh you
- 1:05:06know so I think a lot of people think
- 1:05:09the right number here is at highest
- 1:05:11about. 3 and maybe closer to 0.1 on the
- 1:05:14other hand on the middle class labor
- 1:05:15Supply elasticity seems to be a bit
- 1:05:17higher because more middle class people
- 1:05:21uh tend to say for example women uh in
- 1:05:25the labor force might stay at home if
- 1:05:27the taxes get higher
- 1:05:29um and that leads to about 40% average
- 1:05:33income tax rising to about 80% at the
- 1:05:35top which is really quite Progressive
- 1:05:38right so one possible interpretation
- 1:05:41that Emanuel sias and uh Peter diamond
- 1:05:43and uh Toma come take from this is
- 1:05:46that we should have a much higher and
- 1:05:48more progressive tax system but some
- 1:05:51have also argued that the long run labor
- 1:05:53Supply elasticity is much higher than
- 1:05:54this uh as Adam was sort of suggesting
- 1:05:58okay so let me talk a little bit about
- 1:06:00some of these long run things and
- 1:06:02whether they actually mean that we
- 1:06:03should have uh lower taxes or not okay
- 1:06:08my view is that basically no ambitious
- 1:06:11intelligent person is ever going to
- 1:06:12slack off and just not work hard because
- 1:06:14of incentives and that's why these labor
- 1:06:16Supply elasticities are so low but on
- 1:06:18the other hand the choice of the career
- 1:06:20that you go into is very affected by
- 1:06:22incentives so for example in the 1950s
- 1:06:25most PE there used to be a large number
- 1:06:27of people going into Academia government
- 1:06:30and
- 1:06:31engineering and today almost everybody
- 1:06:33goes into Finance right from top schools
- 1:06:35right and the I think an important
- 1:06:38reason is the relative wage that you
- 1:06:39earn in finance over a lifetime is about
- 1:06:41three or four times higher now relative
- 1:06:44to uh those other professions than it
- 1:06:46was in the
- 1:06:471950s and uh so that increased by about
- 1:06:51three or four times those relative wages
- 1:06:53but in response the relative proportion
- 1:06:55of people going into Finance compared to
- 1:06:57those other things changed by about 10
- 1:06:59times so that suggest a giant
- 1:07:01elasticity right um and so under the
- 1:07:05standard theory that would say giant
- 1:07:07elasticity we should have low taxes
- 1:07:09because if we don't have low taxes
- 1:07:10everyone's going to waste society's
- 1:07:12money by becoming academics government
- 1:07:15you know everyone all these people who
- 1:07:16could be so productive being in finance
- 1:07:18are instead going to do all these low
- 1:07:20productivity professions like
- 1:07:22engineering Academia and government
- 1:07:24right so the the question is do you
- 1:07:26really believe that logic uh you know is
- 1:07:29the world would the world really be
- 1:07:30better if we had lower taxes so that
- 1:07:32everyone went into Finance perhaps you
- 1:07:35know maybe professions get paid
- 1:07:37something that's not exactly the same as
- 1:07:39their social value right um and so this
- 1:07:42is an alternative basis for optimal
- 1:07:44taxation not redistribution but charging
- 1:07:47people a tax rate uh that reflects the
- 1:07:50externalities created by their
- 1:07:52profession and in fact I think this does
- 1:07:54a good job matching what you hear Karl
- 1:07:57Marx writing so Karl Marx doesn't say we
- 1:07:59should tax the rich because they'll keep
- 1:08:02working despite the fact that we tax
- 1:08:05them which is what this model would
- 1:08:07require and Ein Rand doesn't write in
- 1:08:09fact she writes the opposite that oh
- 1:08:11don't tax the rich because they won't
- 1:08:12work if you tax them right uh instead
- 1:08:17the Ein Rand writes that the rich are
- 1:08:18doing wonderful things that they're
- 1:08:19making the world a better place and that
- 1:08:21the poor are you know not doing anything
- 1:08:24good and uh and Marx writes that the
- 1:08:27rich are parasites and that's why we
- 1:08:28should tax them right um and so what we
- 1:08:32did in this paper that I recently wrote
- 1:08:34called Taxation and the allocation of
- 1:08:36talent is that we tried to calibrate all
- 1:08:40of these
- 1:08:41things based on uh the distribution of
- 1:08:44incomes that exist in different
- 1:08:46professions and the views of different
- 1:08:48groups about how much externalities
- 1:08:50different professions have so uh here we
- 1:08:54don't care at all about about
- 1:08:55redistribution we're just trying to
- 1:08:57charge different incomes the
- 1:08:59externalities that they're likely to be
- 1:09:00creating and if you take a view of
- 1:09:02someone from the tea party that leads to
- 1:09:04basically no taxes or even slightly
- 1:09:06negative taxes whereas for Occupy Wall
- 1:09:09Street views you can look at what they
- 1:09:11are this leads to quite high taxes uh
- 1:09:14for my personal views which are very
- 1:09:16similar to my co-author Ben Lockwood it
- 1:09:17leads to pretty modest but positive
- 1:09:19taxes and for my very skeptical
- 1:09:21co-author who doesn't believe that
- 1:09:22there's any externalities it leads to
- 1:09:24near zero taxes but you can just go
- 1:09:26online plug in your own views about the
- 1:09:29productivity of different professions on
- 1:09:31our applet and it will tell you what you
- 1:09:33think optimal taxes should be so this is
- 1:09:34a very different view of of what optimal
- 1:09:37taxation is yeah philli
- 1:09:39um what do you want to look closer to
- 1:09:43the margin of the profession than the
- 1:09:46average because when you change a tax
- 1:09:48rates you're mostly going to be
- 1:09:50eliminating or at least just for small
- 1:09:52changes you're going to be mostly
- 1:09:54eliminating or adding margin yeah I mean
- 1:09:56the the the right way to think about the
- 1:09:57numbers that you plug in is not the
- 1:09:59average externality of people but the
- 1:10:01average externality of the marginal
- 1:10:02people people who just drop in or drop
- 1:10:05out should we look at the Marg average
- 1:10:08exality of marginal home sure yeah
- 1:10:11that's the right way to think about
- 1:10:14it good thanks guys
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