Lecture 2: Development accounting: methods and findings — Transcript
Full transcript
- 0:05Hello. I see people are streaming in
- 0:07still. I wanted to welcome you welcome
- 0:09you all to the
- 0:11second class
- 0:13of STEG's virtual course on key concepts
- 0:15in macro development.
- 0:17Um this is course is offered um
- 0:20course as you know free
- 0:22um from STEG's uh CEPR program
- 0:25which is supported by the United uh
- 0:27Kingdom's a foreign Commonwealth and
- 0:30Development Office. Uh we're thankful uh
- 0:32for them for their support.
- 0:35Um
- 0:37Uh last week uh Richard Rogerson gave
- 0:40the introductory lecture.
- 0:41If you uh missed that
- 0:43um the both the lecture slides and um
- 0:46the talk are available on our website uh
- 0:50via YouTube.
- 0:51Um today we're very thrilled to have
- 0:53Julieta Caunedo
- 0:54who's going to talk about development
- 0:57and income accounting.
- 0:59Um
- 1:00Julieta has uh said for those who are um
- 1:03a panelists uh Julieta has said that you
- 1:06can you know interrupt her with
- 1:08questions. That's fine just as you would
- 1:10in an ordinary class.
- 1:12Um
- 1:13She may you know depending on how many
- 1:15we have she may not be able to answer
- 1:16all of them she might to continue with
- 1:18the the lecture uh just as a normal
- 1:20class would be. Um but otherwise if
- 1:22you're not answering asking a question
- 1:24please mute.
- 1:25Um for those who are joining as
- 1:27participants uh you can type questions
- 1:30into the Q&A you can vote them up. Uh
- 1:33Doug Gollin uh and I um
- 1:36will be answering those in the Q&A.
- 1:39Uh there will also be a
- 1:42um a TA session for this lecture.
- 1:46Um and I actually don't know the timing
- 1:49on that. Julieta do you know the timing
- 1:50for that or Mandy Yes so it's going to
- 1:53be on Monday the same time.
- 1:56Um
- 1:56and I'll explain in a bit what is that
- 1:59session going to be about. Okay.
- 2:02Um
- 2:03and um
- 2:05uh Julieta, we'll leave a little bit of
- 2:06time at the end uh for answering
- 2:09questions uh as well.
- 2:11And I think that's it. Um
- 2:14well, let me thank I should I know, I
- 2:16should
- 2:17uh let me do a couple of the things. One
- 2:19is um
- 2:21um
- 2:22lectures notes for this lecture
- 2:25uh are also available uh online and this
- 2:28will be available uh on YouTube as well
- 2:31uh following the lecture. Um let me also
- 2:34thank uh Mandy Chan and Kirsty
- 2:37um McNeill at CEPR for helping organize
- 2:40this as well. Okay, Julieta, go ahead.
- 2:45All right. Thanks uh
- 2:46uh
- 2:47Daron and and Richard and Joe for for
- 2:50asking me to to this lecture. I'm
- 2:52thrilled to see that there's so much
- 2:54interest in the field and I'm hoping
- 2:57that um STACK will become a home for
- 3:00many students that are thinking about
- 3:02these issues um
- 3:05and I would like to have some sort of
- 3:07references of people that are working in
- 3:08in similar issues and thinking about
- 3:10this. Um so, welcome to hopefully your
- 3:13intellectual home.
- 3:15Um what I want to do today is to
- 3:18uh
- 3:19talk about an important issue, which is
- 3:22development accounting. So, let me just
- 3:25share my screen. So, this is your second
- 3:27lecture uh for the virtual macro
- 3:30development course. This is going to be
- 3:31a course on on income accounting.
- 3:34Um a few organizational issues is that
- 3:38uh Raul Morales, who's a fifth-year
- 3:40student at Cornell, he's going to be uh
- 3:43doing a TA section on Monday.
- 3:46Uh you will see that a lot of what I'm
- 3:49going to do today is going to be
- 3:52measurement
- 3:53and it will require data analysis.
- 3:56Um so I generated small repository that
- 4:01you can access and you will find the
- 4:02link through the slide back and also
- 4:06through the Stack Web page where you can
- 4:09see there is minimal code that will
- 4:11allow you to do a lot of the work that
- 4:13I'm going to describe today and
- 4:15hopefully play around with the data. So
- 4:17what Raul is going to do on Monday is
- 4:19work work with you to make sure that you
- 4:23questions about it if you have questions
- 4:24about it
- 4:26um
- 4:26he will be able to answer those for you.
- 4:28Okay?
- 4:29So um
- 4:31without further ado let me just
- 4:33uh dig in into the issue of the today's
- 4:35lecture.
- 4:36So
- 4:38the first thing to to
- 4:40that you should be asking yourself is
- 4:42you know, what is income accounting?
- 4:44So as as Richard mentioned at the
- 4:46beginning of of his introductory class
- 4:49last week
- 4:51he said, you know, the main question for
- 4:52macro development
- 4:54is the the you know, the observation
- 4:56that
- 4:57there are poor and rich countries in the
- 4:59world and those differences are
- 5:01persistent.
- 5:02And we want to understand why.
- 5:04Okay? But to be able to understand why
- 5:08we need to be able to
- 5:10you know, to understand the sources of
- 5:12those income disparities. So income
- 5:13accounting
- 5:14is going to
- 5:16have a particular approach to answering
- 5:18that question.
- 5:20So you know, we want to know if the
- 5:22reason why poor and richer countries are
- 5:24different is it because richer countries
- 5:27use more labor
- 5:28or because they have better educated
- 5:31workers
- 5:33or because they have more physical
- 5:34capital
- 5:36or the capital that they use is
- 5:37different altogether.
- 5:39Or even more important is it because
- 5:41they have similar you know, factors
- 5:45workers and physical capital
- 5:48but then somehow they managed to do
- 5:50better use of those inputs.
- 5:53Okay?
- 5:55So what income accounting refers to is
- 5:58the approach to answering those
- 5:59questions.
- 6:01So what we are going to do in income
- 6:02accounting is to measure
- 6:04to the best possible each of these
- 6:06ingredients,
- 6:08and then we're going to measure also the
- 6:10relative contributions
- 6:12of each of these ingredients.
- 6:14So for example, it might be that and
- 6:18this is not going to be true in the data
- 6:19just so you know, but it might be that
- 6:21there are large differences in physical
- 6:23capital, but physical capital contribute
- 6:26very little to differences in income
- 6:29across countries. So then those
- 6:31differences are not going to be very
- 6:33important in explaining
- 6:35uh why Malawi is poor and the US is
- 6:38rich.
- 6:39Okay?
- 6:40Now, spoiler alert alert here. I'm going
- 6:43to start from the end. I'm going to tell
- 6:45you what we know so far or what seems to
- 6:47be the consensus in the literature.
- 6:50The current consensus is that
- 6:51disparities in things that we can
- 6:53directly measure like capital and labor
- 6:57account for at most 50% of the
- 6:59differences in income per capita.
- 7:01So there is still a lot
- 7:04that
- 7:05uh
- 7:06you know, that we can't directly
- 7:08measure. We have some ideas of what is
- 7:10generating that additional 50%.
- 7:13Um
- 7:15but from a pure accounting sense,
- 7:18capital and labor only account for about
- 7:20half of the difference that we see.
- 7:23Now, there is an issue with interpreting
- 7:26this finding
- 7:28in the sense that
- 7:31the fact that, you know, how we use
- 7:33those inputs is accounting for 50% of
- 7:37the differences, you know, at the very
- 7:39least,
- 7:41um may feed back into accumulation,
- 7:43right? So,
- 7:45um,
- 7:47it is important to say that the capital
- 7:50and labor, or the capital and labor that
- 7:52we see in an economy, is not exogenous
- 7:54to that economy. How much you invest in
- 7:57Argentina depends on the environment of
- 8:00the economy in Argentina.
- 8:02Okay?
- 8:03And the links to the world, etc., etc.
- 8:07Now, um, as you will see in the rest of
- 8:10this course, of the macro development
- 8:12course, we are going to there's going to
- 8:14be, you know, very important scholars
- 8:16explaining,
- 8:18um, you know, the role
- 8:20of this better use of inputs, and how we
- 8:23think about that, particularly the role
- 8:25of misallocation and the role of
- 8:27frictions. But that's going to come
- 8:29later in the in the in the course.
- 8:31Today I will have very little to say
- 8:33about this.
- 8:34Okay?
- 8:35There is another issue, which is the
- 8:37issue of heterogeneity.
- 8:39Um, you know, how much capital and labor
- 8:42account for
- 8:44in the aggregate may not be the same
- 8:47across sectors or across firms.
- 8:50Okay? So, I'll talk a little bit about
- 8:51that today. And then there is a final
- 8:54question, which is
- 8:56are we doing the best we can in measures
- 8:59measure inputs,
- 9:01um,
- 9:02properly?
- 9:03And the biggest challenge in doing this,
- 9:06when you think of data across countries,
- 9:08is to do it in an harmonized way.
- 9:11Okay? So, I'll get to these issues
- 9:14as we move through
- 9:16through the course.
- 9:17So, let me just tell you what's going to
- 9:19be, uh, the plan for today.
- 9:22I'm going to give you the very basics of
- 9:23this. I'm going to spend quite a bit of
- 9:25time on this,
- 9:26uh, um,
- 9:28because it it is important. The first
- 9:30thing that I'm going to do is I'm going
- 9:32to give you a framework to think about
- 9:33the data.
- 9:35And in general, I think when we are
- 9:37going to go and get our hands dirty with
- 9:40data, it's useful to have a framework
- 9:42because that's
- 9:43an organizing
- 9:45um
- 9:45path
- 9:47that you can use
- 9:48to put order on how you look at the
- 9:50data.
- 9:51Okay?
- 9:52We're not just going to run a million
- 9:54random regressions and come up with
- 9:56something.
- 9:57We want structure. That's what the
- 9:59framework is going to do.
- 10:01And then I'm going to get very detailed
- 10:03on the data we have available,
- 10:06what we can measure, what we know
- 10:09um that are important margins
- 10:12that we should explore further. Um
- 10:15I think what it what is important about
- 10:17this is that, you know, I think the
- 10:20any of you that have a an econ major
- 10:23have had some interaction with with
- 10:25accounting, typically national accounts.
- 10:28Okay, that would be the first or second
- 10:30class in a standard intro to macro or
- 10:32intermediate macro course.
- 10:35And I don't know about you, but I
- 10:36remember the first time I see this, most
- 10:37likely I was rolling my eyes thinking
- 10:39this is not very
- 10:41you know,
- 10:42this is not fun.
- 10:44This is what are we doing this?
- 10:46It turns out that it's actually quite
- 10:47important.
- 10:49Okay? And I don't know, perhaps I've
- 10:51been thinking too much about this in the
- 10:53last couple of weeks,
- 10:54uh but I think it's critical to our
- 10:57understanding of the development
- 10:59process.
- 11:00Okay? So, we need to get dirty with the
- 11:02data somehow.
- 11:04Uh then I'm going to discuss what the
- 11:05main findings of the literature are and
- 11:08different approach approaches to think
- 11:10about um
- 11:12um
- 11:13the accounting per se.
- 11:15And then I'm going to just
- 11:17uh
- 11:19bring up some issues that I think are
- 11:21important, but mostly as a road map to
- 11:23think about open questions that I think
- 11:26are going to be important if if you guys
- 11:28are guys are interested in in field and
- 11:30you shouldn't take this as a as a
- 11:33uh
- 11:35you know, as a roadmap of what people
- 11:37think is interesting. This is mostly
- 11:38what Julieta think it's interesting.
- 11:41Okay?
- 11:42Um
- 11:43So, I'll I'll get to the details as I as
- 11:45I go along into the selected issues.
- 11:48Now,
- 11:49before I get into uh the framework, are
- 11:52there questions?
- 11:56Okay.
- 11:57So, let me get on.
- 12:00Okay. So, the framework that we're going
- 12:03to use to think about income accounting
- 12:06is the one the neoclassical framework.
- 12:10Okay? So, we're going to think of a a
- 12:12production technology that is
- 12:14neoclassical, where output is produced
- 12:17with physical capital K,
- 12:21H or human capital, so a measure of
- 12:24quality-adjusted
- 12:25labor force. So, basically, we want to
- 12:28somehow measure that guys that finished
- 12:31college
- 12:32um are different than people that do not
- 12:36um go to school altogether.
- 12:39Alpha is going to be the capital share,
- 12:42and this technology is going to be
- 12:44neoclassical because we're going to
- 12:46assume constant returns to scale. Okay?
- 12:48That's why the the share on labor is
- 12:50going to be 1 - alpha. And we're also
- 12:52going to assume Hicks-neutral
- 12:54technology.
- 12:55That's going to be A, and that's going
- 12:57to be our measure of total factor
- 12:58productivity.
- 13:00So, so far, I've been talking about this
- 13:03idea of efficiency with which we use
- 13:06inputs.
- 13:07Through the lens of the model, that's
- 13:09going to be this total factor
- 13:12productivity, this A.
- 13:14Okay?
- 13:15Now, if I give you this,
- 13:18one temptation
- 13:20is to say, "Ah, this is nice. This is
- 13:23log-linear."
- 13:24Right? So, So, can take logs on this. If
- 13:27I truly believe that the production
- 13:29technologies are there,
- 13:31um have these particular features that
- 13:33are that are Cobb-Douglas, then I can
- 13:35take logs,
- 13:37and then I should get a linear
- 13:38regression a a linear regression of
- 13:40sorts.
- 13:42Right? So, I have output,
- 13:43I have capital,
- 13:45I have measures of labor input,
- 13:48and then this A that I cannot really
- 13:50measure, this, you know, concept of
- 13:53efficiency with which you use factors,
- 13:56is going to be an error.
- 13:58Okay?
- 13:59Now, there there are
- 14:01many reasons why this is a bad idea.
- 14:04Okay?
- 14:05So, first,
- 14:08for these these um these estimates to
- 14:11give you unbiased estimators of what the
- 14:13what these uh
- 14:15uh you know, factor shares are and the
- 14:17contribution of these of these each of
- 14:19these elements, you need a orthogonality
- 14:21condition between TFP and inputs.
- 14:25And that's very unlikely. This is a
- 14:26story This is what I was saying before,
- 14:28right? If
- 14:30uh it is unlikely that if you live in an
- 14:33economy where inputs are not very well
- 14:36used,
- 14:37I'm going to invest a lot in that
- 14:38economy. Say, I'm going to accumulate
- 14:40capital in there.
- 14:42Okay? So, the orthogonality between the
- 14:44errors and the and the uh regressors
- 14:47here is likely to be violated.
- 14:50And more important, there's a huge
- 14:51literature
- 14:52that um in in in industrial organization
- 14:56that speaks about the challenges of
- 14:58estimating a production function,
- 15:00let alone a production function in the
- 15:02aggregate.
- 15:04So, the income accounting um
- 15:06approach is going to take these
- 15:09production neoclassical production
- 15:10technologies seriously,
- 15:12and it's going to
- 15:13try to measure to the best possible
- 15:16each of these ingredients. Okay?
- 15:20And taking this structural restriction,
- 15:23which is the shape of the production
- 15:24technology, we're going to try to
- 15:26measure what the role of each of these
- 15:28components is. Okay? So, as I said,
- 15:31remember
- 15:33um
- 15:36what things are observable.
- 15:41So, we observe
- 15:43we observe output,
- 15:45GDP,
- 15:47we observe physical capital, and we
- 15:49observe somehow human capital. We'll
- 15:52talk about whether this is really
- 15:53observable or not and what are we
- 15:55missing.
- 15:56But, the idea is that we need some sort
- 15:59of way to figure out what this object
- 16:01is, which is a residual.
- 16:04Okay?
- 16:06Okay.
- 16:09Now,
- 16:11again, another temptation is to say,
- 16:14"Okay,
- 16:15I can measure K, I can measure H, I can
- 16:18measure Y. Let me compute and I I know
- 16:20what the alpha is.
- 16:22And I'll I'll I'll It's okay if you
- 16:24don't know right now uh what the alpha
- 16:26is. I'll I'll tell you how we measure
- 16:27this.
- 16:28Um
- 16:31and then you can say, "Okay, let me
- 16:32account for the the role of capital in
- 16:35this in this uh
- 16:39in this equation."
- 16:40Okay?
- 16:41Now, the problem is that there are
- 16:44important um feedback effects between
- 16:47TFP and investment.
- 16:49Okay? And that we know from the insight
- 16:52of the one-sector growth model.
- 16:55Okay?
- 16:56Again, this is something that um
- 16:59we can get to if you have questions
- 17:02about the details of the one-sector
- 17:03growth model, I'll be happy to take them
- 17:05either at the end of the class or or
- 17:07online, and even Raul can can go through
- 17:09some of these details uh on Monday.
- 17:11Okay?
- 17:13Now, there is a an important takeaway
- 17:15from the one-sector growth model, which
- 17:17is that differences in TFP are going to
- 17:19induce differences in capital.
- 17:22So, if I just say, "Okay, how much of
- 17:23the variation in output is explained by
- 17:25capital?" And I don't take into account
- 17:28the fact that some of the variation that
- 17:30I can't that I see in capital is coming
- 17:33from TFP,
- 17:36then I'm going to I'm just not going to
- 17:37get the right answer, right?
- 17:40But, what is important from the one
- 17:42sector growth model is that we know that
- 17:44the capital output ratio is actually
- 17:47independent of TFP in steady state.
- 17:50What is a steady state? Steady state is
- 17:52an allocation
- 17:54where output
- 17:56uh
- 17:56capital output and capital are constant.
- 18:01Okay?
- 18:02Now,
- 18:03the Euler equation of a standard growth
- 18:05sector one sector growth model, to view
- 18:09um
- 18:10the Euler equation is basically the
- 18:11equation that tells me what the optimal
- 18:14accumulation of capital is along the
- 18:18equilibrium path of the economy. Okay?
- 18:21It's saying that if I invest
- 18:23one unit in capital today, I should get
- 18:26the expected return
- 18:28on capital tomorrow. Okay? Now, that's
- 18:31the equation that you have in the
- 18:32bottom.
- 18:33And it just says
- 18:35um
- 18:37that
- 18:38the this Sorry, that the capital output
- 18:40ratio or the inverse of the capital
- 18:43output ratio, which is the object that
- 18:44you have here,
- 18:45okay? Is going to be a function in
- 18:48steady state. So, this is the the Euler
- 18:50equation
- 18:51in steady state.
- 18:54The capital output ratio is going to be
- 18:56a function of parameters. So, it's going
- 18:58to be constant and independent of TFP.
- 19:02What are those parameters? Well, the
- 19:03parameters are the depreciation rate for
- 19:07capital.
- 19:10Okay?
- 19:11So, you know, if I had a car, I need to
- 19:13go to the garage
- 19:15every year for maintenance, etc. All
- 19:18that because, you know, using the car is
- 19:21going to make it break more often.
- 19:23That's the depreciation rate. Okay? In
- 19:25the context of the neoclassical model,
- 19:27this is just a This is just a a number.
- 19:30Okay? And then it is come factor.
- 19:33Which is going to in steady state in a
- 19:36one sector growth model is going to give
- 19:38you a measure of the impatience of the
- 19:40agents. Okay? How much do I value
- 19:42consuming today versus consuming
- 19:44tomorrow?
- 19:46Okay? And that's why the return to
- 19:47capital, which is
- 19:49um the good that allows me to transfer
- 19:52consumption today to consumption
- 19:53tomorrow, is going to depend on how
- 19:56impatient I am.
- 19:57Okay? But the point is that in a
- 19:59standard neoclassical world
- 20:02in in the world of the one sector growth
- 20:03model, this object in steady state is a
- 20:06constant.
- 20:09Okay?
- 20:11So, here the one sector growth model is
- 20:14giving us a lot of structure on how to
- 20:16look at the data and how to do the
- 20:18accounting. It's saying, "Look, look,
- 20:20look. Yes, you know
- 20:23that
- 20:25K is a function
- 20:28um of A.
- 20:30But honestly, if you just look at
- 20:32capital output ratios, then you're going
- 20:33to kill that relationship.
- 20:35So, let's do that. Okay?
- 20:38So, how do we do that?
- 20:40Well, we're going to rewrite
- 20:42neoclassical production function like
- 20:44this.
- 20:47So,
- 20:50the neoclassical production function was
- 20:53this object here.
- 20:56Oh, sorry. I use L. I should use H.
- 21:03Okay?
- 21:05So, divide by Y over Y to the alpha.
- 21:10And I can collect that down here.
- 21:15Okay?
- 21:16And now
- 21:18I can solve
- 21:20for Y.
- 21:22So, if you solve for Y
- 21:27you're going to end up with this.
- 21:37Okay?
- 21:38So, I basically have
- 21:41the same
- 21:44the same production technology
- 21:48that you had before just rewritten in
- 21:50terms of the capital output ratio.
- 21:54Okay? And that's if I further divide by
- 21:58the head count of the number of workers
- 22:00in the economy, that's L.
- 22:02If I divide by the number of workers, I
- 22:04end up with a equation that I'm going to
- 22:07be using for accounting throughout.
- 22:11What this equation says is that the
- 22:13amount of income per worker in an
- 22:14economy
- 22:16is going to be a function of
- 22:18you know, the efficiency of usage of
- 22:20factors, some modified function of that.
- 22:24The capital output ratio.
- 22:26Okay?
- 22:28And
- 22:30my measure of human capital.
- 22:33Okay?
- 22:36You can write this in logs if that helps
- 22:39the accounting, and I'll show you that
- 22:41given depending on what measure of the
- 22:42accounting you're going to use this this
- 22:44might be useful.
- 22:45Um
- 22:47but for now this is the equation that
- 22:49we're going to be using throughout. Our
- 22:51accounting is going to decompose output
- 22:54per worker
- 22:56into capital output ratios
- 22:59modified by a factor share of capital
- 23:03and a measure of human capital.
- 23:05Whatever is not accounted by the capital
- 23:08labor capital output ratio and human
- 23:11capital is going to be a crew to
- 23:15efficiency of usage of factors, TFP.
- 23:19Okay?
- 23:20Are there questions about this?
- 23:27Good. So, we can move on.
- 23:30Okay. So, let me remind you
- 23:32uh that the the question that we are
- 23:34asked after is how much of the variation
- 23:37in income per worker is accounted for
- 23:39variation in capital output ratios,
- 23:42human capital, and the residual.
- 23:45Okay. So, I basically narrow down the
- 23:47question the the income accounting
- 23:48question.
- 23:50With that, I'm ready to go and tell you
- 23:53how we're going to measure these
- 23:55uh elements.
- 23:59Okay.
- 24:01The good news of living in 2021
- 24:04and not in the
- 24:06second half of the of the
- 24:0920th century is that a lot of work has
- 24:11been done
- 24:12uh to help us measure these objects.
- 24:15Okay?
- 24:16The good news for you guys that are
- 24:18going to be writing the next generation
- 24:20of of
- 24:21you know, research on this topic is that
- 24:23not everything is done.
- 24:25So, there's still questions.
- 24:27Okay. So, um as Richard mentioned last
- 24:31week, uh the the go-to measure
- 24:34uh for macro development is the the the
- 24:37Penn World Tables.
- 24:38Okay?
- 24:39This was a data set that was created in
- 24:42the '60s by uh to measure uh differences
- 24:45in living standards.
- 24:48Okay?
- 24:50Now, there is a question
- 24:53of, you know, whether do want to measure
- 24:56living standards or we want to measure
- 24:58productive capacity?
- 25:00And since
- 25:02basically the productive capacity of an
- 25:04economy
- 25:05and since version 8.0 of the Penn World
- 25:08Table, which is right now run by the uh
- 25:12uh
- 25:13by
- 25:14the University of Groningen and the
- 25:15Groningen Centre for Growth um there
- 25:18have been substantial changes that are
- 25:20going to allow you to to measure
- 25:23productive capacity using the Penn World
- 25:25Tables. Okay?
- 25:27Now my
- 25:29two cents here before we even get into
- 25:31the data is that in general you should
- 25:33be very careful uh on how you set the
- 25:35data and record the vintages that you're
- 25:37using because there this data is in
- 25:40constant um
- 25:42um change. People are you know the the
- 25:46the um
- 25:47uh the group that is putting together
- 25:49this data is working really hard to make
- 25:52as many improvements to the data as
- 25:53possible. So that means that the changes
- 25:55changing. The data change.
- 25:57Now what I did for this class is I
- 25:59generated a repository,
- 26:01a GitHub repository. For those of you
- 26:04that are not familiar with with Git,
- 26:07um you can pretty much just link on the
- 26:10on the slides. It's going to take you to
- 26:13a webpage where you can download all the
- 26:15material that is relevant for these
- 26:17things. You don't need to work in that
- 26:18environment.
- 26:19Um you will need to have access to a
- 26:23software uh like Stata to be able to run
- 26:25the code that you have there.
- 26:27But if you don't want to, the the code
- 26:30that even or if you don't want to or you
- 26:31don't have access to to that software
- 26:33right now,
- 26:34um the code is annotated in a way that
- 26:37is going to be kind of a class on its
- 26:39own on what are the steps that you need
- 26:41to be able to measure each of these
- 26:43inputs if you were to do income
- 26:45accounting. Okay?
- 26:47And and Raul will review uh that with
- 26:50you on Monday.
- 26:53Okay, so without uh
- 26:57more details about this, although I'm
- 26:58happy to talk about them if the audience
- 27:00has questions, let me just talk about
- 27:02how we measure output and work. So, I'm
- 27:04going to start with the output part of
- 27:06this, then I'm going to talk about
- 27:07employment and labor.
- 27:09Okay? Um
- 27:11Again, the good thing is that coming
- 27:13after Richard, Richard talked a lot
- 27:14about these things. So, uh you will see
- 27:16some repetition. But, it's good to see
- 27:18it twice. Hopefully, the second time it
- 27:20is clearer.
- 27:21Um
- 27:22nominal output uh
- 27:25is going to get um typically from the
- 27:26national accounts, okay?
- 27:29But, what we're interested is in a
- 27:30measure of of real outputs or a
- 27:32unit-free measure of of uh how much of
- 27:36an economy produces, okay?
- 27:39And then the question is, okay, then
- 27:40that means if I have a nominal number, I
- 27:43I and I want to turn it real, what do I
- 27:45do? I divide by the the the price level.
- 27:48Okay?
- 27:50Now, what is this price level?
- 27:53This was a concern uh
- 27:56um it draws some some discussion among
- 27:58economists and and of the two candidates
- 28:01to do something like this
- 28:03are, okay, maybe I want to denominate
- 28:06say the GDP
- 28:09in Brazil
- 28:11in dollars
- 28:13and now it is directly comparable to
- 28:17the US GDP in dollars.
- 28:20Well, the one way to do that is to just
- 28:23use the exchange rate of the real to um
- 28:26to the dollar
- 28:28and transform everything in dollar
- 28:30values.
- 28:31Okay? Now, the problem is that the
- 28:33exchange rates are good measures of
- 28:36um
- 28:37of tradeable goods.
- 28:39Okay? And something that economies um
- 28:43uh
- 28:44in particular Bela Balassa and Samuelson
- 28:47figured out early on is that well, there
- 28:50are departures from what is called
- 28:52purchasing power parity. Okay, so let me
- 28:54let me get a little bit into into this.
- 28:58So, the the PPP prices,
- 29:01and I'll tell you what they are in a
- 29:02second, are built from the international
- 29:04comparison program. Okay?
- 29:06Um which basically surveys goods that in
- 29:11theory should be of comparable quality
- 29:12across countries. Okay, and they do a
- 29:14lot of effort to compare similar goods.
- 29:17But more important, they really want to
- 29:20have the same basket of goods priced in
- 29:24different countries.
- 29:26Okay?
- 29:27What does this basket include? It
- 29:29include consumption and investment good
- 29:32prices.
- 29:33It also includes tradeable and
- 29:35non-tradeable goods. So, a haircut,
- 29:37okay?
- 29:38And an apple.
- 29:40But it doesn't necessarily include
- 29:43imports and exports. If you go to the
- 29:44documentation of Penn World Tables,
- 29:46you're going to see that after version
- 29:489.1, they have done a lot of effort in
- 29:52trying to have proper deflators for
- 29:55exports and imports. Okay?
- 29:57The reason why when I do this income
- 29:59accounting exercise, I'm going to be
- 30:01thinking of closed economies is that it
- 30:05turns out that that component of export
- 30:06and import from a pure accounting
- 30:08exercise, it's not
- 30:11is not important in explaining the large
- 30:13disparities in income across countries.
- 30:15Okay? And there is a nice paper um
- 30:18written by the uh Penn World Tables um
- 30:21you know, group discussing the
- 30:23discussing this issue. Okay?
- 30:26Now, in general, the issue of comparing
- 30:28prices on poor and rich economies
- 30:30is a complicated ma- matter. So, what is
- 30:33the issue here? The issue is that the
- 30:35bundle of goods that people consume in
- 30:37India is
- 30:39systematically different from the bundle
- 30:41of goods that people consume
- 30:44in um
- 30:46in Peru.
- 30:47Okay?
- 30:48Staple goods are different, right?
- 30:52You know, the diets of people change
- 30:54dramatically across countries that are
- 30:56even in in the same income
- 30:59uh bracket. Okay?
- 31:01So,
- 31:03you know, if you want to if you're
- 31:05interested in the issue of comparing
- 31:07prices across country, I think the the
- 31:08paper I did on Al Hester is a is a good
- 31:10reference
- 31:12to think about this.
- 31:13Now, how does the
- 31:16the PPP price is
- 31:18how is it constructed?
- 31:20Just so we have an idea of what is that
- 31:21we are actually doing
- 31:24when we deflate using
- 31:26um PPP prices instead of exchange rate.
- 31:30So, the the may the basic idea is that
- 31:33if we use the exchange rate, we're only
- 31:35pricing goods that are tradeable, okay?
- 31:38Whereas, if you use the PPP prices,
- 31:40you're really comparing the same bundle
- 31:42of goods across countries. Why is that
- 31:44important? I'll tell you in the next
- 31:46slide.
- 31:47Okay?
- 31:48Now, how do you construct these bundles
- 31:50these bundle of these prices, sorry?
- 31:53What I want you to get from these uh
- 31:55from from the procedure
- 31:58is that you're basically going to have
- 32:02an aggregator, so the sum across
- 32:04countries,
- 32:05of a price of a consumption good.
- 32:07Suppose that all that there is in the
- 32:08economy are apples. Okay?
- 32:11So, you're going to you're going to
- 32:12price apples
- 32:14uh in different countries, that's PJC.
- 32:19Sorry, let me just mark this.
- 32:22You're going to price
- 32:23prices in different countries, that's
- 32:24PJC, okay?
- 32:26And then,
- 32:28um
- 32:28you're going to weight this Sorry,
- 32:31you're going to turn these prices into a
- 32:33common
- 32:35unit, okay? Using an exchange rate,
- 32:38that's going to be the PPP exchange
- 32:40rate. I'll get back to this in a second.
- 32:42But then you're going to weight these
- 32:43prices, the price of an apple in
- 32:45Bangladesh versus the price of an apple
- 32:48in Brazil, uh using
- 32:52the domestic consumption in country J of
- 32:56that apple relative to the world
- 32:59consumption of apples.
- 33:02Now,
- 33:04a direct implication of this is that
- 33:08because the weights have um the size of
- 33:11the economies here, prices from rich
- 33:13countries are going to have more weight
- 33:15than prices from poor countries.
- 33:17Okay?
- 33:19That's first takeaway.
- 33:21Second takeaway
- 33:23is the following.
- 33:28This is what is called the Penn effect
- 33:30or the Balassa-Samuelson effect.
- 33:32So, this is what I did. I took
- 33:36I took
- 33:40You know,
- 33:41output in current in current dollars
- 33:44from the as reported in Penn World Table
- 33:47in a country, in this case I picked
- 33:49Argentina, my country of origin, China,
- 33:53and Finland, a rich economy. Okay?
- 33:56And then I did two things. I could the I
- 33:59could turn this into common units using
- 34:02the exchange rate
- 34:04or using the PPP deflator.
- 34:10Okay?
- 34:11Now, what you see is that in relatively
- 34:14poor countries, like Argentina and
- 34:16China, GDP looks bigger
- 34:20when you deflate with PPP than when you
- 34:22deflate with exchange rates.
- 34:25Why is that? Fir- Sorry, first of all,
- 34:27this difference seems small because I'm
- 34:29using a log um a log um these are logs
- 34:33of output per worker. I should have
- 34:35changed the scale. I'm sorry for that.
- 34:37I'll I'll do it. But basically, the
- 34:39difference in these in terms of, um,
- 34:42PPP dollars is about $5,000.
- 34:46Okay? So, for a country with an income
- 34:47per capita of about 20,000, which is
- 34:49Argentina, this is a big deal.
- 34:52Okay?
- 34:53Now, why is that when I deflate with
- 34:55PPP, I get, uh, that poor countries have
- 34:59seem to have higher value added?
- 35:01Well, the Balassa-Samuelson effect says
- 35:03the following. If I have an economy
- 35:06where the production you are,
- 35:08uh, relatively less productive in
- 35:10tradables, okay?
- 35:12What that's going to generate is that
- 35:14the overall price level of the economy
- 35:15is going to be cheaper. Not only of
- 35:17tradables, also of non-tradables.
- 35:20Okay? This is the idea that if
- 35:24you know, if you want somebody to help
- 35:26you in your house,
- 35:27in the US or in Europe,
- 35:29in terms of the income of the average
- 35:31guy out there in the street, it's going
- 35:34to be pretty expensive.
- 35:36Okay? It's going to be a good chunk of
- 35:37your income.
- 35:38Whereas, if you are in Turkey, in places
- 35:41in South America,
- 35:43you know, getting somebody to come and
- 35:45help in your house is going to be
- 35:47relatively cheaper.
- 35:49You know, somebody helping in your house
- 35:51is highly non-tradable.
- 35:54So, how is this possible? Well, that's
- 35:55the Balassa-Samuelson effect.
- 35:57It's the idea that even the prices of
- 35:59non-tradables are going to be cheaper in
- 36:01poor countries because the price of
- 36:04because they're relatively less
- 36:05efficient in producing tradables.
- 36:08So, what that's going to generate is
- 36:09that if you look at income disparities
- 36:12deflated using exchange rate, you're
- 36:15going to overestimate
- 36:17the differences in income across
- 36:19countries.
- 36:21Okay? So, the idea is that poor
- 36:24countries are going to look even poorer
- 36:26because you're not adjusting for the
- 36:27fact that the non-tradable goods
- 36:29actually
- 36:30are actually cheaper
- 36:32in those countries.
- 36:34Okay, are there questions about this?
- 36:41Okay, so if I want to measure income
- 36:43income per worker, now I need to go to
- 36:45the denominator. I need a measure of
- 36:47employment.
- 36:49Well,
- 36:50then I need to
- 36:52uh take a call. I could just use
- 36:54headcounts
- 36:55or I can use hours work.
- 36:58Until Penn World Table
- 37:00um
- 37:019.1,
- 37:03there were actually no harmonized
- 37:05measures of average uh working hours
- 37:09available
- 37:10uh within the Penn World Tables.
- 37:12Even now in version 10, you're going to
- 37:15see that there is available a measure of
- 37:17hours work,
- 37:19but the measure that is available there
- 37:21is not going to available is not going
- 37:22to be available for all the countries in
- 37:24the sample and for the whole time
- 37:26period. Okay?
- 37:27So, a lot of the you know, the two
- 37:30handbook chapters that were uh assigned
- 37:32as as as reading material for this
- 37:35course still use measures of workers
- 37:39that are just headcounts, employment.
- 37:41Okay?
- 37:43Now, why is this important? Well,
- 37:46there's a paper by Biggs, Fulton, and
- 37:47Lagakos that shows that our works
- 37:50decrease with development.
- 37:52So, people in rich countries work less
- 37:54hours than people in poor countries.
- 37:57Why is this important? Because if in my
- 38:00accounting,
- 38:01I compute, remember the object here is
- 38:05output per per worker.
- 38:08If I divide by a systematically
- 38:12um um
- 38:14lower level of employment in poor
- 38:17countries,
- 38:18then I'm going to then I'm I'm to tend
- 38:20to increase the amount of output per
- 38:22work.
- 38:23But what happens is that the amount of
- 38:24hours worked is higher in in poor
- 38:27countries.
- 38:29Okay? So, what you have
- 38:31um
- 38:33in the what you have in this in this in
- 38:35the exercise that you have in the
- 38:36repository is you have the alternative
- 38:39to use either employment that maximizes
- 38:42the sample or to use employment times
- 38:45the average hours worked, which is going
- 38:46to give you a total number of hours
- 38:49uh um
- 38:50full-time equivalent workers uh in an
- 38:53economy. Okay? So, you can play around
- 38:55with the with the with the
- 38:58uh data that way.
- 39:00Okay.
- 39:01Sorry. I wanted to ask something related
- 39:03with these working hours. Yes.
- 39:05I was thinking when I was reading this
- 39:06paper in the recommendation that um
- 39:09is there any way to control for the
- 39:12actual hours worked? Because I can't
- 39:14imagine that we have very long shifts
- 39:16like they have the example of Egypt with
- 39:1857 hours. I highly doubt that people,
- 39:22you know, like committing a big effort
- 39:24working for 60 hours a week. I mean, I
- 39:27don't know. For me it's kind of odd.
- 39:29And coming I mean I I'm I'm Spanish and
- 39:31here we have longer working shifts than
- 39:33for example France, Germany, stuff like
- 39:35that. But maybe we we relax a little bit
- 39:38during the working hours, right? Because
- 39:40it's a longer shift. Yeah, so you're
- 39:42Okay, if I get correctly
- 39:44uh your your question, what you're
- 39:46trying to or you're asking is
- 39:50are all hours uh
- 39:52do all hours entail equal effort? And if
- 39:55what I'm really after is a measure of
- 39:56employment, I agree with you. I don't
- 39:58think we have
- 40:00uh even for developed countries, I don't
- 40:02think we have good measures of of this.
- 40:05Okay.
- 40:06Um now, the fact that there are 57 hours
- 40:09in Egypt, I don't think it's very
- 40:10surprising in the sense that
- 40:13uh if you ever walk through Cairo, you
- 40:15will see that people barely sleep. So,
- 40:18uh
- 40:18it's not so surprising that the hours
- 40:20are are longer there. But I agree with
- 40:22you, there is an issue of of uh
- 40:24productivity as signs to this. And in
- 40:26part that's going to be coming in in the
- 40:29amount of output that you produce per
- 40:30hour work.
- 40:31Right?
- 40:32Yes. So, that would be the direct
- 40:34measure of of that efficiency.
- 40:37Mhm. Okay?
- 40:40Okay.
- 40:41So,
- 40:42um
- 40:47So,
- 40:49uh
- 40:52In measuring the the the next thing that
- 40:54we need to measure is the capital output
- 40:56ratio.
- 40:57Okay?
- 40:58Now,
- 40:59the current
- 41:00So, think about what is capital in an
- 41:02economy. Capital in an economy are
- 41:04production lines, the trucks, the cars,
- 41:08um
- 41:09but also, you know, the the land that
- 41:12you have available, the buildings.
- 41:14Now,
- 41:16Pingle table considers the following
- 41:18categories. So, they're going to
- 41:19consider machinery, computer and
- 41:21communication equipment, transportation,
- 41:23structures,
- 41:24and other assets, in particular, IPP,
- 41:27which is intellectual property products,
- 41:30and software.
- 41:32The reason why I'm highlighting
- 41:33computers and communication equipment
- 41:35and IPP and software is because these
- 41:37are equipments that particularly since
- 41:39the 2000 have had rapid changes
- 41:42in
- 41:43uh
- 41:44um
- 41:45in that option of of this type of
- 41:48investment and the prices.
- 41:50Um
- 41:52and are potentially important in the
- 41:55economy, and at least in developed
- 41:57economies, in the economies that are
- 41:58coming up and are becoming available to
- 42:00us. If you go to the data set that uh
- 42:03Richard also mentioned last week, uh the
- 42:05total economy data set, there you're
- 42:07going to see that you have different
- 42:09time series time series for capital, for
- 42:12what is called
- 42:13uh communication equipment, ICT
- 42:15equipment, and ICT equipment, sorry,
- 42:19and non-communication equipment. Okay?
- 42:22So, if you're interested in these
- 42:24particular capital goods, there is
- 42:26different disaggregations that are
- 42:27available in sister data sets to the
- 42:31Penn World Table.
- 42:32Now, there is a question here of what is
- 42:35productive capacity versus
- 42:37productive capital versus natural
- 42:39resources.
- 42:40So, for example,
- 42:41countries
- 42:43in in the Middle East that mostly live
- 42:45out of oil rents are going to look
- 42:49extremely rich because they produce a
- 42:51lot with a very little input.
- 42:54But, it's not clear that the standard
- 42:56neoclassical framework is what really,
- 42:59you know, a good theory to think about
- 43:01the output produced or the output the
- 43:03the richness of the workers producing in
- 43:06in those economies.
- 43:07So, Caselli and Feyrer wrote a paper
- 43:09where they're taking these ideas
- 43:11seriously,
- 43:13trying to clean up what is productive
- 43:16capital versus natural resources.
- 43:20And
- 43:21a crude adjustment to output
- 43:26that you can do is to just eliminate
- 43:29from output the rents that come from
- 43:30natural resources.
- 43:32The World Bank has put together a data
- 43:34set that is now available through the
- 43:36World Development Indicators that is
- 43:38going to allow you to know how much of
- 43:40your GDP are rents associated to these
- 43:43natural resources.
- 43:45So, what you will see is what I did in
- 43:46the accounting that I'm going to present
- 43:48is I eliminate I took away from the
- 43:51value of GDP
- 43:53the
- 43:54the rents from natural resources. Cuz if
- 43:56you don't do that, you're going to have
- 43:58countries like, you know, Qatar and
- 44:01Benin being super rich. They're
- 44:03basically living out of their
- 44:06their oil rents. Okay?
- 44:09Uh, so how do you properly measure
- 44:11capital?
- 44:13Well, the standard way to measuring
- 44:15capital is the permanent inventory
- 44:16method.
- 44:18Uh, which means that you're going to use
- 44:21uh, the following law of motion.
- 44:23So, suppose you have the stock of some
- 44:25equipment I, in this case trucks,
- 44:28and you want to know how much stock
- 44:29you're going to have in each period of
- 44:30time. That's K.
- 44:32There was a typo in the notes, so I
- 44:33added a plus one on the
- 44:36on the
- 44:38uh,
- 44:40on the left-hand side here. I'll update
- 44:42it after the class, so you have the link
- 44:44corrected. Okay?
- 44:46So, how much capital am I going to have
- 44:48tomorrow? Well, I'm going to have
- 44:50whatever investment I have today, plus
- 44:52the value of the undepreciated stock.
- 44:55Where delta here is the depreciation
- 44:57rate for the stock.
- 44:59Okay?
- 45:00Now, this is the stock of trucks. Then I
- 45:03need to aggregate.
- 45:04Uh,
- 45:05to aggregate it, I'm going to use some
- 45:07weights to aggregate trucks to computers
- 45:09to structures to buildings. Okay?
- 45:12Now,
- 45:13uh, a couple of issues. Let me first
- 45:15focus on on the question on top. Okay?
- 45:19Now,
- 45:21what the what the framework says is that
- 45:23delta should be physical depreciation.
- 45:26Now, the measures out there for physical
- 45:28depreciation typically include economic
- 45:30depreciation, which is this idea that,
- 45:33you know, you have your phone,
- 45:36and your phone makes calls,
- 45:39sometimes, you know, it allows you to
- 45:41text,
- 45:42and if you have a, you know, a
- 45:44smartphone, then you are even able to
- 45:46connect to the internet.
- 45:47Fine. The services that you have are
- 45:49what they are.
- 45:51But, you know, 2 years after you hold
- 45:53that phone,
- 45:54that phone is worth half the price.
- 45:58It may be exactly the same phone, still
- 46:00making calls, still connecting to the
- 46:02internet.
- 46:04Why is that? Well, that's economic
- 46:05obsolescence.
- 46:06The reason why the price of that capital
- 46:08good falls is because there are better
- 46:10goods available in the economy.
- 46:12Okay?
- 46:14Now, the second issue that is important
- 46:16to understand in measuring in in
- 46:19measuring capital stocks is that you
- 46:20need some sort of
- 46:23initial stock of capital to be able to
- 46:26generate this iteration, right? You see
- 46:27investment in each period, but you need
- 46:29to have some initial capital to use
- 46:31here.
- 46:33Okay, so there are two options. One
- 46:34option is to take uh seriously a
- 46:37one-sector growth model here, call it
- 46:40the solar model, but a one-sector growth
- 46:41model,
- 46:43and say, "Okay, capital in the initial
- 46:45period is going to be uh investment
- 46:48adjusted by the depreciation rate of
- 46:51that capital,
- 46:52which
- 46:55For some reason, this is not working.
- 46:57Okay, the depreciation rate of that
- 46:58capital,
- 47:00and the growth rate of the economy.
- 47:03All right? That's going to be my
- 47:04initial.
- 47:05The second approach that um uh people,
- 47:09in particular after Penn World Table 8,
- 47:11have been using is to uh
- 47:14calibrate
- 47:16so that the measure of the stocks that
- 47:18you generate are consistent with the
- 47:21share of capital to to output, which
- 47:24happens to be, at least Finstra in 2015,
- 47:27this is a AR paper,
- 47:29uh added used that this ratio is stable
- 47:32across countries and and time.
- 47:34This is a different version of this is a
- 47:36uh
- 47:37um
- 47:38uh the Kaldor facts. Okay?
- 47:41Now, the problem is when you go
- 47:42empirically and look at the data, it
- 47:45doesn't seem that this is so constant.
- 47:48So, the newer version of Penn World
- 47:50Table, and here you have the link in the
- 47:53in the in the
- 47:56in the slide deck, so you can see the
- 47:59increase in the the change, sorry, in
- 48:02this in this ratio.
- 48:05Um so, basically, what they're doing is
- 48:06they're trying to match
- 48:08countries, given their income level, to
- 48:11that curve that they estimate using the
- 48:13data from all these countries through
- 48:15time. Okay?
- 48:17Uh sorry, that seems a little bit big,
- 48:19but that was the best I could do, given
- 48:21that I didn't want to spend more than um
- 48:23you know, 5 minutes talking about how
- 48:25you construct this this initial capital
- 48:28stocks. If you have questions about
- 48:30them, I'll be happy to answer at the end
- 48:32or offline.
- 48:37Okay.
- 48:40Okay. So, the second issue is that now
- 48:43we figure out how to measure the stock
- 48:44of trucks. Now, we need to somehow add
- 48:48trucks
- 48:49to computers.
- 48:51How do we do that? Well, we're going to
- 48:52have some weighted averages of these
- 48:54stocks.
- 48:55Okay.
- 48:57There are various ways to do that. One
- 48:59way is to use
- 49:02the expenses in the sorry, the stock of
- 49:04capital value that whatever prices for
- 49:06the capital you have, divided the
- 49:08overall value of the capital stock in
- 49:11that economy at the point in time.
- 49:14The other way to do this is instead of
- 49:15using the prices of the capital, is to
- 49:18use the rental prices, the rental rates.
- 49:22Why does this matter? Well, because the
- 49:24first approach is going to tend to
- 49:26overstate the value of long-lived
- 49:28assets.
- 49:30So, the idea is that if I have a truck
- 49:32that can be around for 50 years and
- 49:36whose price is fairly stable through
- 49:38time, and it's giving me very little
- 49:40service in each period, then I'm going
- 49:42to tend to overestimate the value of the
- 49:44truck and underestimate the value of the
- 49:47phone.
- 49:48Right?
- 49:52Using these rental rates,
- 49:54um,
- 49:54is perhaps a desirable
- 49:57better way to measure capital services
- 49:59associated to these long-lived assets.
- 50:03And the way they're going to infer these
- 50:05rental rates is using the concept of the
- 50:08user cost of capital.
- 50:10So, how do we do this? We want to
- 50:11measure what is the user cost What is
- 50:14the user cost of capital?
- 50:17Well, one way to do that
- 50:20is to
- 50:23do the following.
- 50:27So, suppose I can
- 50:30you know, I can buy a truck or I can put
- 50:33the money in the bank.
- 50:34Okay?
- 50:35So, suppose that the price of the truck
- 50:38is PIT.
- 50:40PIT. If I put it in the bank, it's going
- 50:43to give me a return RT.
- 50:46Or
- 50:48I can buy the truck, rent it,
- 50:53Okay?
- 50:56And then I'm going to end up with the
- 50:59undepreciated value of the truck.
- 51:02Okay? Suppose it was There was some wear
- 51:05and tear.
- 51:06And I can sell it back in the market.
- 51:09At whatever price it's available for
- 51:12trucks tomorrow.
- 51:13I think we all understand that equation,
- 51:15right?
- 51:16So, what this is saying is that if it is
- 51:18true that you are indifferent when you
- 51:20buy this truck, you're indifferent
- 51:21between putting the money in the bank
- 51:23and getting whatever return or whatever
- 51:24return you get when you purchase the
- 51:26truck the truck, then the user cost of
- 51:28capital can be inferred as a residual.
- 51:32Okay? So, basically, the equation that
- 51:34you have here for the user cost of
- 51:36capital is just solving through for
- 51:40R, which is the user cost.
- 51:42Now, it turns out that after you do all
- 51:44this work,
- 51:45and again, you can play with this
- 51:46through the code that you have available
- 51:47in the repository. You're going to see
- 51:50that the amount of capital services
- 51:53are not so different.
- 51:56Okay?
- 51:57And this is just an empirical issue.
- 52:01I'll be happy to talk more about
- 52:02adjustment to the investment series, but
- 52:05I just don't have time to go through all
- 52:06this. It's already, you know, um hitting
- 52:09the limits. Now, the next thing, so we
- 52:11have two more things that we need to
- 52:13measure. We measure output, we measure
- 52:16the capital output ratio, we need to
- 52:17measure the factor share for capital,
- 52:20and we need to measure human capital.
- 52:21Where are these factor shares estimated?
- 52:24Well, under the assumption of constant
- 52:25returns, you can literally uh infer the
- 52:27capital share as a residual between the
- 52:30labor share uh of income,
- 52:33basically how much all the workers in
- 52:35this economy are paid for as a fraction
- 52:38of GDP, um
- 52:40um
- 52:42Sorry, as a residual of that that uh
- 52:44that labor income over overall. Now, the
- 52:47time series suggest that this number
- 52:50that the capital share is about a third.
- 52:53I mean, this is kind of uh
- 52:55um
- 52:56color facts.
- 52:57Now, the cross-country data, when you go
- 52:59and do this with the with the national
- 53:02accounts data,
- 53:04shows that there are massive
- 53:05differences. Okay?
- 53:07What I'm going to do for the exercise
- 53:09that you have in the code, and what also
- 53:10Hall and Jones and Jones in his chapter
- 53:13does is to adjust the assume that alpha
- 53:15is 1/3.
- 53:17Now,
- 53:18uh Daggolyn,
- 53:20uh or Steen Daggolyn, uh who should be
- 53:23somewhere in the audience,
- 53:24um had an influ- influential paper where
- 53:27he said, "Well, the issue is that you
- 53:29really need to consider
- 53:31self-employment."
- 53:32And in national accounts, typically
- 53:34self-employment is treated as capital
- 53:35income.
- 53:36So, once you adjust for self-employment,
- 53:38which happens to be disproportionately
- 53:40more prevalent in poor countries, then
- 53:43you get an in- a labor share that varies
- 53:47between
- 53:48a third and point eight. So, the capital
- 53:50share is going to go sorry, two thirds
- 53:52and point eight. And the capital share
- 53:55is going to go between one third and
- 53:56point two. That's much smaller
- 53:58variation.
- 54:00Penn World Table has their own
- 54:02estimates, the new one, the Penn World
- 54:04Table 10 has the new estimates of the
- 54:06factor shares, but again, there is a lot
- 54:07of variation. So, that's why we didn't
- 54:09use it. It's in the code. You have the
- 54:11code written, you can play around with
- 54:12it.
- 54:15Okay, finally,
- 54:17human capital.
- 54:19I'm going to give you a brief overview
- 54:20of how we measure human capital. You're
- 54:22going to have the full supplemental
- 54:24lecture that Turchin is going to teach
- 54:26to get into the nitty-gritty of of how
- 54:29we measure human capital, how we do it
- 54:30properly, and what is at the frontier.
- 54:33Now, the idea of measuring
- 54:36human capital is basically this idea
- 54:39that I think Juan had before, that you
- 54:41know, workers or an hour of a worker is
- 54:46not the same.
- 54:48Neither through the day nor, you know,
- 54:51of workers of different skills. So, for
- 54:53example, a college educated worker is
- 54:57going to have different input than an
- 55:00educated worker. Okay? Now, the
- 55:02differences between those two workers
- 55:04are as what what we're going to call
- 55:06efficiency units.
- 55:08So, the idea that if my efficiency unit
- 55:10is one, it's basically that's a
- 55:12normalizing factor. Think that an
- 55:14educated worker
- 55:17produces half of what an educated worker
- 55:20produces, then the efficiency units of
- 55:22the uneducated worker are going to be
- 55:24half
- 55:25of the other one. And it's just a way to
- 55:28add
- 55:30factors of production, in this case
- 55:31human capital, in a way that take into
- 55:33account this heterogeneity that we know
- 55:35exists in the data.
- 55:37Now, the typical way to map this
- 55:39efficiency or just think about how a
- 55:40worker is different is to say, well,
- 55:44workers differs in the level of
- 55:46schooling
- 55:47and also in their experience in the in
- 55:49the job, right? There are people that
- 55:50have been doing the same job for 30
- 55:51years. It cannot be that they produce
- 55:53the same thing that the guy that just
- 55:55started the job. Okay?
- 55:58Now, in in a very nice paper, Bills and
- 56:00Klenow argue that there are also
- 56:01differences
- 56:03in
- 56:04kind of the quality, even if you have
- 56:06the same schooling and the same
- 56:08experience in Bangladesh and in France,
- 56:12it turns out that the quality of the
- 56:14input that you're putting in is
- 56:15different and that's going to generate
- 56:16differences in return. Okay? So, what
- 56:19I'm going to do today, I'm going to
- 56:20assume that the quality of that that
- 56:24schooling is the same across is
- 56:26identical across countries.
- 56:28And then we're going to parameterize
- 56:29that function fee, which is going to
- 56:30give me the returns to to to schooling
- 56:34and and experience as two terms. One
- 56:37that is just a function of schooling,
- 56:38the other one that G that depends on my
- 56:41experience.
- 56:42Now, what is the the the story of this
- 56:45specification, it goes back to the long
- 56:48labor literature that thinks about
- 56:50earnings in terms of
- 56:52in Syrian regression. Okay? The idea
- 56:54that the earnings that you earn are a
- 56:57function are a function of your
- 56:58schooling in this case. So, in the
- 57:00Mincer specification,
- 57:02uh an additional
- 57:04uh year of schooling, so as
- 57:07uh higher is going to give me theta more
- 57:11in terms of income.
- 57:14Um
- 57:16And then the idea that experience
- 57:19also matters, it has a return, and it
- 57:21actually the return to experience is uh
- 57:24convex. Okay?
- 57:26Now,
- 57:28in this cross-country analysis, what
- 57:30we're what we're going to do is we're
- 57:31going to follow the Penn World Table uh
- 57:34for their own measures of human capital.
- 57:37So, in particular, what they do is
- 57:39they're going to use the educational
- 57:40attainment data from Barro and Lee, and
- 57:42also they are merging now uh data from
- 57:45Cohen, Soto, and Lecker that what that
- 57:48what it does is
- 57:50uh it controls
- 57:52it has better measures of what
- 57:54attainment means in a harmonized way
- 57:55across countries, okay? And then the the
- 57:58returns are only going to have returns
- 58:00to schooling to education, and this is
- 58:02going to come from uh
- 58:04Sakellaropoulo's '94, okay? Now, the
- 58:08human capital index that they're going
- 58:09to generate is going to have this uh
- 58:13piecewise linear
- 58:14uh shape that is going to say that the
- 58:17first four years of schooling
- 58:20is going to uh increase each year is
- 58:23going to increase your income by uh 13%
- 58:26points.
- 58:27Then, the next four to eight years is
- 58:30going to increase your income by 10% and
- 58:33uh sorry, this is a typo. This should be
- 58:37larger than eight.
- 58:43So, if X is larger than eight, sorry, my
- 58:46handwriting is not best here. Let me
- 58:48just do this.
- 58:51So, if S is larger than eight, then
- 58:54you're going to get an additional income
- 58:56uh a marginal income of uh 7%. Okay?
- 59:01Now, as you see
- 59:03the Penn World Table right now is using
- 59:05a measure of human capital that doesn't
- 59:07depend on experience.
- 59:09Now, what How important is experience?
- 59:12Well, there is a nice paper by Lagakos,
- 59:13Moll, Porzio, Tian, and and Toth Ralston
- 59:17that argue that the experience profile
- 59:19is steeper for workers with higher
- 59:21schooling.
- 59:22Okay? But, then not only that, which is
- 59:23important for for income per capita, is
- 59:25that the experience wage profiles are
- 59:27twice as deep in rich in rich than in
- 59:30poor countries.
- 59:32So, the idea is that the you know, the
- 59:34return for for your
- 59:37for staying one more year in the job is
- 59:39much higher in rich countries than in
- 59:41poor countries.
- 59:42So, what that's going to do is that it's
- 59:43going to change the shape of your human
- 59:46capital input
- 59:48into that production technology. And I
- 59:50really encourage you to to read the
- 59:51paper through, get to the nitty-gritty,
- 59:53and I guess Todd will will uh revisit
- 59:56some of these these issues next week.
- 59:58Julieta, I have another question. Uh I
- 1:00:00was When I was checking this part as
- 1:00:02well, I was thinking like
- 1:00:04um I mean, yes, they they they were
- 1:00:06saying that in um underdeveloped
- 1:00:08countries they have more experience on
- 1:00:09average, right? But then I I I was
- 1:00:11wondering if I mean, and now you're
- 1:00:12mentioning that you actually have more
- 1:00:13return to experience in the in Western
- 1:00:15countries, in more developed countries.
- 1:00:17So, I was wondering like this may be a
- 1:00:20problem related with um job switching
- 1:00:22and probably sector switching. Maybe in
- 1:00:25underdeveloped countries they don't
- 1:00:26really switch jobs that much because I I
- 1:00:28I don't know if you have any insight of
- 1:00:29this because I don't know if they switch
- 1:00:31jobs more, sectors more. I don't I don't
- 1:00:33have any idea.
- 1:00:34Um
- 1:00:36the evidence seems to be that there is
- 1:00:38more switching, but the evidence is very
- 1:00:41new. The paper to look into this is also
- 1:00:43a paper that uh Schulman is writing with
- 1:00:46uh Kevin Donovan.
- 1:00:48Um if you just go through the webpage,
- 1:00:50you're going to see, and the data is um
- 1:00:52the data is available. There is another
- 1:00:54paper
- 1:00:55to look into this
- 1:00:57uh by uh uh
- 1:00:59Markus Poschke, but I'm not sure if they
- 1:01:02have the occupational turnover.
- 1:01:05So, so poor countries switch more?
- 1:01:09That uh I think that's the I think
- 1:01:11that's the the takeaway. The problem is
- 1:01:13in the paper that really thinking about
- 1:01:16uh unemployment employment flows.
- 1:01:18They're not thinking about occupation
- 1:01:20occupation flows. I was thinking a bit
- 1:01:22of maybe some sort of friction, right?
- 1:01:24Like yeah, so
- 1:01:26The data I know these guys are thinking
- 1:01:28about these issues. I don't think we
- 1:01:30have a definitive answer. Not that I
- 1:01:31don't not that I know. Maybe Joe or Doug
- 1:01:35we have a better answer about that, but
- 1:01:37I don't think we know right now.
- 1:01:39In part because it's very difficult to
- 1:01:40measure.
- 1:01:42So think about it. The real challenge in
- 1:01:43doing all these things is that you need
- 1:01:45to measure this stuff in a harmonized
- 1:01:47way across the world.
- 1:01:49And that's the the the harmonization.
- 1:01:50It's not because conceptually we think
- 1:01:51it's difficult. It's just because it's
- 1:01:53difficult to measure this harmonized
- 1:01:55way.
- 1:01:57Okay, so with that let me just get to
- 1:02:01the results.
- 1:02:02Jingong, do you have a question? Yeah,
- 1:02:04can I question about the price
- 1:02:05adjustment? So earlier we talked about
- 1:02:07using PPP to adjust the different prices
- 1:02:09in different countries. And
- 1:02:12for instance, if we select the US as a
- 1:02:13base country, we we may want to convert
- 1:02:15all the other
- 1:02:18GDP into the US dollars. And this is
- 1:02:21this is a important for doing a
- 1:02:23cross-sectional comparison. But what if
- 1:02:24we want to do a time series comparison?
- 1:02:27If we for instance want to compare the
- 1:02:29the GDP of China over time and after
- 1:02:31converting
- 1:02:33the same Y into USD, then
- 1:02:35which inflation which deflator should we
- 1:02:38use? The US one?
- 1:02:38are different
- 1:02:40I guess the answer depends on what is
- 1:02:42that you're
- 1:02:44you're really interested in. Even when
- 1:02:46you do growth accounting, which is kind
- 1:02:48of the
- 1:02:50the same exercise that I'm running here
- 1:02:53across countries, but for the country
- 1:02:54through time.
- 1:02:56You want to have a PPP measure of these
- 1:02:58things exactly because of the issues
- 1:03:00that I was discussing before. The
- 1:03:01exchange rates are just a measure of the
- 1:03:05prices of tradeable goods.
- 1:03:07Right? And we know that there are
- 1:03:08systematic different In a world where
- 1:03:10the world
- 1:03:12Sorry, and we know that there are
- 1:03:13systematic differences in the prices of
- 1:03:15non-tradeable across countries and
- 1:03:17through time.
- 1:03:19So, something that the newest version of
- 1:03:21the Penn World Table does, so it used to
- 1:03:23be that they would use a benchmark year
- 1:03:26from the ICP
- 1:03:27and they would use that to deflate the
- 1:03:29whole thing.
- 1:03:30The newest versions of the Penn World
- 1:03:31Table, what they're doing is they're
- 1:03:33using different benchmark years to
- 1:03:35deflate different time periods.
- 1:03:38Which is exactly what you want because
- 1:03:39the bundles of goods are changing
- 1:03:42through time and across countries. So,
- 1:03:44they make
- 1:03:45they make sure to to generate the
- 1:03:48deflator that takes the same bundle
- 1:03:50through time across countries.
- 1:03:52Okay? So, the answer, if you're going to
- 1:03:54do a a growth accounting exercise, is to
- 1:03:56use PPP.
- 1:03:58And the reasoning is what I was what I
- 1:04:00was saying is that
- 1:04:02we live in a world where uh there are
- 1:04:05deviations for prices in power parity
- 1:04:07and the reason for that is the
- 1:04:09Balassa-Samuelson effect. The idea that
- 1:04:11if you're less productive in the
- 1:04:12tradable good, your overall price level
- 1:04:15also of the non-tradables is going to be
- 1:04:16lower.
- 1:04:17Okay? So, there are systematic
- 1:04:19differences in the relative prices of
- 1:04:21haircuts to um shoes.
- 1:04:25Okay?
- 1:04:27Is there any more question Are there any
- 1:04:28more questions?
- 1:04:33Okay.
- 1:04:34So, after all this work
- 1:04:37uh let's just try to see what we can
- 1:04:40find. So, how much variation in income
- 1:04:42per worker is accounted for variation in
- 1:04:45factors of production?
- 1:04:47And how much is just deficiency in using
- 1:04:49those factors or the of the
- 1:04:51productivity?
- 1:04:53Well, what I did here is I literally
- 1:04:55replicated the table that is in Jones
- 1:04:572016, the handbook the handbook chapter,
- 1:05:00with the same countries, with the only
- 1:05:02difference that I used the data in 2017
- 1:05:04instead of the data in 2010.
- 1:05:07Also, my natural adjustment uh my
- 1:05:10adjustment for natural resources is not
- 1:05:12what exactly what he did.
- 1:05:14Um
- 1:05:16um
- 1:05:17but
- 1:05:18you know, in terms of the ranking of
- 1:05:19countries, what you're going to see is
- 1:05:21that there was some reshuffling
- 1:05:23here on the top,
- 1:05:25but the ranking among poor countries
- 1:05:26pretty much what he had there.
- 1:05:29Now, how do you interpret this thing?
- 1:05:31I'm going to pick Argentina because
- 1:05:33that's the the country I I come from and
- 1:05:35it's rather arbitrary. I could have
- 1:05:37picked any any other uh one, but also
- 1:05:40because the numbers are easy.
- 1:05:42Okay? So,
- 1:05:44um
- 1:05:44what we did here is we normalized the
- 1:05:46United States to one in each of the
- 1:05:48factors. Okay?
- 1:05:50So, what are the income differences
- 1:05:53between Argentina and the US?
- 1:05:55Well, one way to think about it is
- 1:05:58to do one over 0.4. That's give you
- 1:06:01approximately 2.5.
- 1:06:04Okay?
- 1:06:05And now let's try to think of how much
- 1:06:07of this comes
- 1:06:09from measured inputs, which are the
- 1:06:11first two terms, and how much of that
- 1:06:13comes from the residual. This is what is
- 1:06:15produced in this uh last column here.
- 1:06:19How do we measure that? Well, we know
- 1:06:21that
- 1:06:23what comes from
- 1:06:25TFP or the C is one over 0.5. That gives
- 1:06:29you a ratio of two.
- 1:06:31Okay?
- 1:06:33So, what is that 0.6 coming from?
- 1:06:35Well, we know that capital there is
- 1:06:38basically no differences and there is
- 1:06:40about the
- 1:06:41um
- 1:06:43uh
- 1:06:440.2 differences in human capital.
- 1:06:46Okay? So, if you do
- 1:06:491 + 2 +
- 1:06:51uh
- 1:06:521.2,
- 1:06:54you're going to get
- 1:06:56um
- 1:06:58Yeah, you're going to get about 0.6.
- 1:07:02Okay? Which is the number that you have
- 1:07:04in the last column.
- 1:07:06And you do the same for each country.
- 1:07:08And then what I did is I produced the
- 1:07:10averages for the whole sample, not just
- 1:07:12the ones that are presented in this
- 1:07:13table, and then uh I computed the same
- 1:07:17exercise. There you get to about 70%.
- 1:07:21Now, why is that?
- 1:07:23Well,
- 1:07:25what seems to happen is that if I comp
- 1:07:28if I plot the share due to TFP,
- 1:07:32okay? The share of income disparities
- 1:07:34due to TFP, the last column that I
- 1:07:36showed you before, on the Y axis,
- 1:07:38against income per capita
- 1:07:41income per worker, sorry, in the log
- 1:07:42axis, then what you're going to see is
- 1:07:45that
- 1:07:47there is a strong negative relationship.
- 1:07:49Okay?
- 1:07:50So, what this is saying is that
- 1:07:53poor countries, sorry, that
- 1:07:56TFP
- 1:07:57explain more most of the difference
- 1:08:01between those poor countries and the US
- 1:08:03than it does in rich countries.
- 1:08:06All right? That's takeaway number one.
- 1:08:10Takeaway number two, which you typically
- 1:08:12don't see in income accounting
- 1:08:13exercises, but I thought it was I was
- 1:08:14just curious and I thought it was
- 1:08:16important to see, is that these effects
- 1:08:19are
- 1:08:20I would say stable. Yes, there is a bit
- 1:08:23of a of a trend in the contribution of
- 1:08:25TFP.
- 1:08:26I would say it's it's stable. It's
- 1:08:27around 60%.
- 1:08:29Okay? The contribution of of TFP.
- 1:08:32There is a little bit of a trend and
- 1:08:33that's a question too of measurement,
- 1:08:35etc., etc. So, hopefully, you know,
- 1:08:37we'll figure we'll figure that out soon.
- 1:08:40Now, another approach to thinking about
- 1:08:43the contribution, instead of doing that
- 1:08:45exercise that I that I did before, is to
- 1:08:48think about a variance decomposition
- 1:08:50inspired measure. This is what Caselli
- 1:08:52in his handbook paper does.
- 1:08:54Okay?
- 1:08:55Um
- 1:08:58So, you can take a factor only component
- 1:09:01of output per worker.
- 1:09:03Okay?
- 1:09:04That's basically everything that we can
- 1:09:05measure. Capital output ratios, factor
- 1:09:08shares, human capital.
- 1:09:10And then you can have uh then you can
- 1:09:12write output per worker as
- 1:09:15this measure, which is what we don't
- 1:09:17know,
- 1:09:19you know, TFP, and then
- 1:09:22what we can what we actually see.
- 1:09:27If you do a log variance decomposition
- 1:09:29of this, you're going to see that the
- 1:09:31variance of log output is going to be
- 1:09:34explained by the variance of
- 1:09:36um
- 1:09:37the residual term
- 1:09:39plus the variance of the measure the
- 1:09:42things that you can measure
- 1:09:44and the covariance between those two.
- 1:09:48Now, what is the income accounting
- 1:09:50exercise in this environment
- 1:09:52uh
- 1:09:53translated to this environment?
- 1:09:55Remember, what we're trying to answer is
- 1:09:56how much of the income variation is
- 1:09:58accounted for variation in factors of
- 1:09:59production.
- 1:10:01Well,
- 1:10:02this is
- 1:10:04uh equivalent to asking what's the
- 1:10:06variation in output when
- 1:10:10say the productivity of all the
- 1:10:11countries is the same.
- 1:10:12But if the productivity of all the
- 1:10:14countries is the same, then the
- 1:10:15covariance between log Z and log uh and
- 1:10:18what you can measure is going to be zero
- 1:10:21because Z is flat, okay?
- 1:10:23Now, the key measure that Caselli
- 1:10:25proposed is to use a measure of success,
- 1:10:28basically how much we can explain from
- 1:10:30measure stuff, as uh the variance in the
- 1:10:34log of
- 1:10:35uh output measure versus the variance
- 1:10:38that we actually see in the data.
- 1:10:41Alternatively, you can follow the Cleno
- 1:10:43Rodriguez Claray uh approach, which is
- 1:10:46to say, "No, no, well, this covariance
- 1:10:48term is important. I'm going to assign
- 1:10:49it equally between TFP and um measured
- 1:10:54inputs."
- 1:10:57Now, if you do that,
- 1:10:59uh the measure of success that you get
- 1:11:01is the following. So, in our data in
- 1:11:042017, you get that the variance of
- 1:11:06output per worker is about 0.65.
- 1:11:10The variance of output per worker that
- 1:11:11you can measure is uh
- 1:11:14a third
- 1:11:16of that uh sorry, 18%. So, then what you
- 1:11:19can actually measure of the variance is
- 1:11:21about the third.
- 1:11:22Everything else, this is consistent with
- 1:11:25the number that we got from from the
- 1:11:26other measure.
- 1:11:27About 70% on average is stuff that we
- 1:11:30cannot properly measure. Of course, I'm
- 1:11:33using a very uh you know, the way I
- 1:11:35measure capital and labor is as a
- 1:11:37standard as it can be. The papers that I
- 1:11:39mentioned through the whole data section
- 1:11:42um
- 1:11:43increase the the the share accounted for
- 1:11:47things that you can actually measure,
- 1:11:49okay?
- 1:11:50So, um this is this is the plain vanilla
- 1:11:53accounting that you can that you can
- 1:11:55cover.
- 1:11:56Now, one more question and and with this
- 1:11:58I likely close. I leave the selected
- 1:11:59issues for for the discussion. I'll
- 1:12:01bring them up uh
- 1:12:03I'll discuss them if if we want because
- 1:12:05I really want to hear from you if you if
- 1:12:07you have uh questions and thoughts.
- 1:12:09So, let me finish with with the
- 1:12:11following.
- 1:12:12Um
- 1:12:14so far we have been thinking of an
- 1:12:15economy as a homogeneous unit, okay,
- 1:12:18where the production technology is what
- 1:12:20it is.
- 1:12:21But, we know that there are sectorial
- 1:12:24disparities, right? The production in
- 1:12:26agriculture is not the same as as in
- 1:12:28non-agriculture.
- 1:12:30Potentially, the production of tradables
- 1:12:31and non-tradables is different.
- 1:12:34Um
- 1:12:36so, I'm going to follow here the the
- 1:12:38exercise that Caselli did
- 1:12:40and I'll tell you why why this is
- 1:12:42important.
- 1:12:43Uh it's not arbitrary that we're picking
- 1:12:45agriculture and non-agriculture.
- 1:12:48So,
- 1:12:49uh
- 1:12:50you can think of total output in an
- 1:12:51economy as
- 1:12:54the
- 1:12:55um
- 1:12:57an employment weighted um average
- 1:13:00between the output produced by
- 1:13:02agriculture and the output produced
- 1:13:04everywhere else.
- 1:13:05Why is this important? Well, because
- 1:13:07pretty much all the workers in poor
- 1:13:09countries are employed by the
- 1:13:12agriculture sector.
- 1:13:13Okay?
- 1:13:15And pretty much none of the
- 1:13:18workers in the rich countries are
- 1:13:20employed in the agriculture sector.
- 1:13:23Now, the challenge for which we can't
- 1:13:25just have
- 1:13:26you know, disaggregations for many many
- 1:13:28sectors is that to be able to construct
- 1:13:31this these measures of output at the
- 1:13:33sector level, you need PPP deflators by
- 1:13:35sector. And those are actually very hard
- 1:13:37to construct.
- 1:13:39For the case of agriculture, uh
- 1:13:41Restuccia, Yang, and Zhu
- 1:13:43uh constructed measures using producer
- 1:13:46prices that came from
- 1:13:48uh Food and Agriculture Organization,
- 1:13:50FAO. Okay?
- 1:13:52There is a an early paper by Baldi and
- 1:13:54Solow on the manufacturing and service
- 1:13:57uh service PPP using firm-level data um
- 1:14:01that I actually wasn't aware of uh until
- 1:14:04recently, and I think it's you know,
- 1:14:06it's nice to to take a look in in terms
- 1:14:09of uh giving us ideas on how to measure
- 1:14:11these these PPPs for broad sectors.
- 1:14:14Now, going back to agriculture.
- 1:14:16So, how
- 1:14:19So, one way to think about this is to
- 1:14:21say, "Okay, how important is
- 1:14:23agriculture?" We know that countries
- 1:14:26rich and poor countries are very
- 1:14:28different in their employment shares.
- 1:14:30And they're also uh potentially
- 1:14:32different in how much This is a typo,
- 1:14:34sorry.
- 1:14:38This is A bar, and this is A bar because
- 1:14:40this is the share outside agriculture,
- 1:14:43and this is the output outside
- 1:14:44agriculture.
- 1:14:46All right, so how important this
- 1:14:48So, the exercise that Caselli does is
- 1:14:50the following. He says, "Look,
- 1:14:53real output per worker the uh the log
- 1:14:55variance for the period that he's using
- 1:14:57is 1.1.
- 1:15:00Suppose that let me just rewrite the the
- 1:15:04the equation here. So, output is
- 1:15:08the price in agriculture, the output in
- 1:15:11agriculture, and the labor share in
- 1:15:12agriculture.
- 1:15:16Uh you have it here. Sorry, I have it
- 1:15:17down there.
- 1:15:19Okay.
- 1:15:20So, what happened if
- 1:15:23I put the output in agriculture that the
- 1:15:26US has, and I change nothing else?
- 1:15:29All that I do is I give the poor
- 1:15:30countries
- 1:15:32uh sorry, I give all the countries the
- 1:15:35output that the US has.
- 1:15:37Then the log variance in output per
- 1:15:38worker pretty much disappears.
- 1:15:42Right?
- 1:15:45Alternatively, suppose I don't want to
- 1:15:48give them the technology of the US in
- 1:15:49agriculture, I give them the technology
- 1:15:51of the US in non-agriculture. This
- 1:15:54subject.
- 1:15:55What do I get? Well, it drops by about a
- 1:15:58half.
- 1:15:59So, yes, it's important.
- 1:16:01But obviously it's not as important as
- 1:16:03difference in agriculture. What happened
- 1:16:05if I give them the employment shares of
- 1:16:06the US?
- 1:16:08Again, it decreases, you know,
- 1:16:12uh quite a bit, close to 70%.
- 1:16:16So, these two components, the labor
- 1:16:19share in agriculture and the um the
- 1:16:22output in agriculture, seems to be key
- 1:16:24drivers of income disparities across
- 1:16:27countries.
- 1:16:28Okay?
- 1:16:29And that's why there has been a lot of
- 1:16:32um research on these issues.
- 1:16:35Now, because I I spoke too much, maybe I
- 1:16:38I I was awfully um
- 1:16:41um
- 1:16:44optimistic on how much I
- 1:16:46could discuss.
- 1:16:48Let me just uh leave you with the
- 1:16:50following thought.
- 1:16:52So,
- 1:16:54you know, trade trade economists tend to
- 1:16:56think of an economy between, you know,
- 1:16:57tradeable and non-tradeable goods.
- 1:17:00Growth economists think about
- 1:17:02consumption goods and investment good
- 1:17:04capital.
- 1:17:05And then the macro development
- 1:17:06economists think about, you know,
- 1:17:07agriculture, manufacturing,
- 1:17:10and services.
- 1:17:12But the the big idea that I want to
- 1:17:14leave you with is that
- 1:17:16relative prices in all these sectors,
- 1:17:18and hopefully you saw that from the
- 1:17:19measurement issues that we have
- 1:17:21discussed in, right? We went from
- 1:17:22consumption to investment to tradeable
- 1:17:24and to non-tradeable to sectors.
- 1:17:26There is a lot of information about
- 1:17:29productivity that comes in relative
- 1:17:31prices.
- 1:17:33Okay? So, while this the measurement of
- 1:17:35relative prices seems like an a geeky
- 1:17:37issue, it's actually quite important
- 1:17:39because it has a lot of information
- 1:17:40about productivity difference, which are
- 1:17:42first order to understand income
- 1:17:44income disparity.
- 1:17:46Okay? So, with that,
- 1:17:49I'm going to just let you go, and I'm
- 1:17:52going to open the floor uh in the last
- 1:17:5510 minutes uh for questions.
- 1:18:00Raul, do we have any any questions from
- 1:18:02the chat?
- 1:18:05Hello, Julieta.
- 1:18:07Hello.
- 1:18:08Hello, yeah. Um thank you very much for
- 1:18:10the class.
- 1:18:12Okay. Uh I would just like to raise a
- 1:18:15point. Okay. If I may. Okay.
- 1:18:18Mhm.
- 1:18:18Yeah. Uh
- 1:18:20According to findings, yeah, we
- 1:18:24we we notice that development accounting
- 1:18:27highlights human capital as an important
- 1:18:30factor of economic growth.
- 1:18:33And when we look into the literature,
- 1:18:36social capital is not a point which has
- 1:18:40been widely discussed.
- 1:18:42And however,
- 1:18:45uh we can see that there are some
- 1:18:48economic benefits of social capital.
- 1:18:51For example,
- 1:18:51you Can you be a little bit more
- 1:18:53explicit about what I have an idea what
- 1:18:55social capital means, but I just want to
- 1:18:57make sure that we we are on the same
- 1:18:59page. What do you mean by social
- 1:19:00capital? Yeah, uh maybe some aspects
- 1:19:03like
- 1:19:05uh confidence,
- 1:19:06integrity, lectures
- 1:19:09Mhm. among people.
- 1:19:11And yeah, what I'd like to raise is that
- 1:19:15uh we have many uh some economic
- 1:19:18benefits of social capital like people
- 1:19:21may find job uh through social networks,
- 1:19:25for example.
- 1:19:26And trust encourages more efficient use
- 1:19:29of of credit. And also
- 1:19:32um social networks uh
- 1:19:35are important for regional groupings of
- 1:19:38innovative activity sectors
- 1:19:41because they they can enable
- 1:19:43dissemination and sharing of knowledge,
- 1:19:47which are really important for economic
- 1:19:50growth, too.
- 1:19:51So, my question is uh
- 1:19:54what's your opinion about that? How can
- 1:19:56we take into account social capital? So,
- 1:20:00uh personally, I think that social
- 1:20:02capital may reinforce human capital and
- 1:20:05then uh contribute to to uh economic
- 1:20:08growth.
- 1:20:09Okay. Thank you. Thanks. That's a very
- 1:20:11good question, Samson. So, uh
- 1:20:13the answer comes into in two parts. The
- 1:20:16first one is that a lot of the features
- 1:20:19that we think about uh in terms of
- 1:20:21social capital are actually or say
- 1:20:23you know,
- 1:20:24um also the the way you manage uh your
- 1:20:27workers, etc., etc., those are all going
- 1:20:30to be
- 1:20:31uh in the accounting framework that I
- 1:20:34presented are going to be sucking to
- 1:20:36this productivity term.
- 1:20:38How efficiently do you use the same
- 1:20:41input of production?
- 1:20:43The The answer is in terms of that
- 1:20:45particular channel,
- 1:20:47I don't know what's the in the in an
- 1:20:49accounting sense, I don't know what the
- 1:20:50I can't don't know the to pinpoint what
- 1:20:52the the the actual magnitude of that
- 1:20:55effect is. But what I would encourage
- 1:20:57you to think about is the fact that uh
- 1:21:00you know, the
- 1:21:02differences in in what you will need is
- 1:21:06that the differences there are
- 1:21:08systematic differences in social capital
- 1:21:11across
- 1:21:12uh
- 1:21:13across countries and across income.
- 1:21:16And that I'm you know, I'm not a
- 1:21:18specialist in the field of social
- 1:21:20capital, but I'm not I'm not sure if
- 1:21:23that is that is true and if anything uh
- 1:21:26if it will go in the right direction,
- 1:21:28right? Is social capital more valuable?
- 1:21:32Uh likely social capital is more
- 1:21:33valuable in in poor economies than it is
- 1:21:35in rich economies, but I'm really in the
- 1:21:37world of hypothesizing
- 1:21:39at this point because I don't know what
- 1:21:40the actual answer to that is.
- 1:21:42So
- 1:21:43as I said, it's stuck in the Z effect.
- 1:21:47Uh since the real question is whether
- 1:21:49are systematic differences in income uh
- 1:21:53in terms of social capital and I am not
- 1:21:55aware of uh um
- 1:21:58uh research that documents this thing.
- 1:22:00There is a lot of research in terms of
- 1:22:02management practices, but that's a
- 1:22:04slightly different than what you're
- 1:22:05asking.
- 1:22:06Okay? Yeah, because uh yeah yeah,
- 1:22:10because uh
- 1:22:11I can see that
- 1:22:13uh when we talk about economic growth,
- 1:22:16uh we we we may not see the the direct
- 1:22:19effect, but when it comes to welfare,
- 1:22:23you know, I really think that
- 1:22:25uh social capital should not be put
- 1:22:27aside because it's not only a matter of
- 1:22:30what do you know, but it also involve
- 1:22:34who do you really know. Yeah, yeah,
- 1:22:36yeah.
- 1:22:37Okay.
- 1:22:38Thank you. Uh, so I would rather do you
- 1:22:41figure out your your your speaker
- 1:22:44situation? Okay, yes. Can you hear me
- 1:22:46now?
- 1:22:46Mhm. Okay. Yeah, my question is actually
- 1:22:49with respect to the concept of
- 1:22:51informality.
- 1:22:52Uh, do you think the TFP accounts for
- 1:22:55this?
- 1:22:56Yeah, so this is this is a a nice uh,
- 1:22:59question.
- 1:23:00Some of that is accounted there. The
- 1:23:02real issue is whether we're measuring
- 1:23:05employment properly.
- 1:23:07Right?
- 1:23:07Okay. Cuz the issue of informality is
- 1:23:09that you have a large uh, and this is
- 1:23:11what what that guy in paper is
- 1:23:13is in part about. Uh,
- 1:23:15he uses to measure properly uh, input
- 1:23:18shares. But,
- 1:23:20you know, self inform informality and
- 1:23:22self-employment, at least in developing
- 1:23:24countries, go uh, very close together.
- 1:23:27Okay? And then the question is the
- 1:23:28measures of employment that are there
- 1:23:30are measures of formal employment.
- 1:23:33Uh, but
- 1:23:34there is room to to think about uh,
- 1:23:37informality better. I know the people
- 1:23:39table
- 1:23:40um, has been doing an effort to put
- 1:23:43informal workers to measure informal
- 1:23:45workers uh, in a better way. But do you
- 1:23:47really share that view that was shared
- 1:23:49in the paper with respect to
- 1:23:52um, comparing self-employment and
- 1:23:54informality? I I think there there is a
- 1:23:56kind of difference between the two.
- 1:23:58No, there is a difference between the
- 1:23:59two, but what I'm saying is that a lot
- 1:24:01of the informal workers happen to be
- 1:24:04there are many of them that happen to be
- 1:24:06self-employed.
- 1:24:07That's all. That's on one side, but we
- 1:24:10we see characteristically that in
- 1:24:11developing economies
- 1:24:13uh, a huge chunk of transactions are
- 1:24:16done in the informal sector that are not
- 1:24:18accounted for.
- 1:24:19And and it's kind of deliberate or also
- 1:24:23because
- 1:24:23Oh, I see. I see. There are There are
- 1:24:25two issues. Okay, so there are two
- 1:24:26issues. It's not only whether you count
- 1:24:28employment or not, there is also the
- 1:24:29issue that GDP whether GDP properly
- 1:24:32measures the employment.
- 1:24:33Absolutely. Absolutely. Absolutely.
- 1:24:35There is actually an ice paper by
- 1:24:37Paulina Restrepo Echevarria that takes
- 1:24:39this idea very seriously seriously and
- 1:24:41tries to adjust measures of GDP by the
- 1:24:44size of the informal economy.
- 1:24:46And I think my understanding is that
- 1:24:48national So, to the extent that the
- 1:24:50informal economy is reflected in the
- 1:24:52national accounts, this is going to show
- 1:24:54up in
- 1:24:56in the bank world tables. The bank world
- 1:24:58tables are not going to produce new
- 1:25:00adjustment to the national accounts.
- 1:25:02One is my understanding is that in the
- 1:25:05developing world there is
- 1:25:07strong efforts to measure the informal
- 1:25:10sector in the value of of output. Some
- 1:25:13of them you know, the the measure of
- 1:25:15that success is yet to be seen, but I
- 1:25:17totally agree with you that
- 1:25:20you know, properly accounting for the
- 1:25:21size of the informal economy is actually
- 1:25:23quite important in understanding
- 1:25:25differences in income. Could you please
- 1:25:26reference the paper? Because for me that
- 1:25:28is very important because
- 1:25:29Yes, so let me just take your name. I'll
- 1:25:32I'll follow up with you with a link to
- 1:25:34the to the
- 1:25:36to the paper. Okay.
- 1:25:40Are there any more questions? Yeah, can
- 1:25:42I ask one more question, please?
- 1:25:44Yes. are also asking about this paper.
- 1:25:47Who was that?
- 1:25:49Some people in the chat are also asking
- 1:25:51about the
- 1:25:52the this paper. Okay, yeah. The the the
- 1:25:55question about informality, maybe you
- 1:25:57share it on the platform for
- 1:25:59What I can do is I can share it because
- 1:26:02I need to look for the link. So, what I
- 1:26:03can do is I can
- 1:26:06I can put it in my webpage and I can ask
- 1:26:08Mandy to post it in the in the
- 1:26:12in the website. I can also put it in the
- 1:26:14repository where you have the rest of
- 1:26:16the materials for the class. I think
- 1:26:17that was really nice. Yeah, thank you.
- 1:26:19All right.
- 1:26:20Okay, thank you. Andres, do you have a
- 1:26:22question? I believe I just posted a link
- 1:26:25to that paper in the chat. Ah, okay.
- 1:26:27Awesome. Thank you. I think it's the
- 1:26:28right one. Thanks, Doug.
- 1:26:31Yeah, thank you, Julieta. Um so,
- 1:26:35I've been thinking,
- 1:26:37is there some way you can disentangle
- 1:26:40like
- 1:26:41allocative uh efficiency with uh
- 1:26:44technological efficiency?
- 1:26:47Um may- maybe by assuming in sectors or
- 1:26:49something like that. I get the
- 1:26:50impression that
- 1:26:51um Yeah, so if you notice, um I think
- 1:26:55this is related to things that
- 1:26:57you know, there is a whole course
- 1:26:59related to this to this issue. And part
- 1:27:01of what the the the lectures that are
- 1:27:03coming up are going to do is they're
- 1:27:04going to put you at the frontier of what
- 1:27:06we know in terms of allocative
- 1:27:07efficiency versus difference differences
- 1:27:10in technology. So, a lot of those issues
- 1:27:12are going to be addressed in the sec- in
- 1:27:13the module on misallocation.
- 1:27:16Okay? I think Richard and Pete Klenow
- 1:27:18are going to present like what our know-
- 1:27:21the state of knowledge is
- 1:27:23uh in terms of how much of this is
- 1:27:26uh you know, differences in technology
- 1:27:29and how much of this is proper
- 1:27:31misallocation. I think your question is
- 1:27:33a good question in terms of something
- 1:27:34that I wanted to discuss, but I didn't
- 1:27:36have time to, which is this idea that um
- 1:27:40you know, different countries may be
- 1:27:41choosing different technologies given
- 1:27:44the endowments and the frictions that
- 1:27:45they face. Okay? And this is the idea in
- 1:27:48the paper by uh Caselli and Coleman, uh
- 1:27:52the world technology frontier.
- 1:27:54Okay? There they're taking seriously
- 1:27:57skilled and unskilled workers
- 1:27:59and they're thinking about factor bias
- 1:28:01technical change. So, basically, the
- 1:28:03idea that technical change affects
- 1:28:04skilled workers differently than
- 1:28:05unskilled workers.
- 1:28:07But also this idea that and I think what
- 1:28:09is uh so impressive about about that the
- 1:28:11findings that paper is that it seems
- 1:28:14just from a an accounting sense that
- 1:28:18poor countries use unskilled workers
- 1:28:21better, quote unquote, productivity
- 1:28:23terms than rich countries. So, that
- 1:28:25suggests that they're using different
- 1:28:27technologies.
- 1:28:28So, it's not that they're in a vacuum.
- 1:28:29It's not that, "Oh, well, we're not
- 1:28:31adopting the technology
- 1:28:33um
- 1:28:34and we're just worse, right? They're
- 1:28:36they're basically adapting the use of
- 1:28:38factors to the technologies that they
- 1:28:40can adopt. And they're adopting
- 1:28:42technologies that are complementary
- 1:28:44potentially to uh the factors that they
- 1:28:47have available. The question is to what
- 1:28:48extent they're doing that um in a
- 1:28:51constrained efficient way and uh to what
- 1:28:54extent this is, you know, misallocation
- 1:28:56of of of factors of of production. But
- 1:28:58that there's going to be a whole module
- 1:29:00about that. So, hopefully a lot of those
- 1:29:02questions will will come back again
- 1:29:04then. Sue, do you have a question?
- 1:29:07Uh hello. I have a very question.
- 1:29:09Hello.
- 1:29:10Uh so, I think in the accounting like
- 1:29:14equation that we have talked about like
- 1:29:17like assumes that there's So, so
- 1:29:20basically capital and labor are like
- 1:29:23separable, so there are no like
- 1:29:25like like uh so, any complementary
- 1:29:28relationship between them?
- 1:29:29Yes. Yeah, so I Mhm.
- 1:29:32Yeah, so what like if there is like the
- 1:29:35like difference in the usage of like
- 1:29:38factors, then
- 1:29:40uh what if whether it might affect the
- 1:29:43our income accounting or not. That That
- 1:29:45was my question.
- 1:29:46Thank you, Sue. So, this is another
- 1:29:48thing that I I didn't have a chance to
- 1:29:50discuss uh and it's part of my selected
- 1:29:53issues.
- 1:29:54There is a
- 1:29:55uh so, there is there is an issue on how
- 1:29:58we think about
- 1:30:00you know, measuring inputs and
- 1:30:02aggregating the efficiency of say, for
- 1:30:04example, workers or even capital, right?
- 1:30:06Capital of different vintages that are
- 1:30:08different. The way kind of the
- 1:30:10efficiency units or the standard
- 1:30:12approach to doing these things is to add
- 1:30:14them up linearly. And if anything, you
- 1:30:17know, compensate for the fact that say a
- 1:30:19high school worker is going to produce
- 1:30:21slightly more than a
- 1:30:24an uneducated worker. And the way we
- 1:30:27infer those differences in production is
- 1:30:29by looking at wage differentials.
- 1:30:31Okay?
- 1:30:32Now, there is a nice exchange between
- 1:30:36Ben Jones is all referenced in the
- 1:30:38slides. Ben Jones,
- 1:30:40Caselli and Ciccone.
- 1:30:42And then Ben Jones again.
- 1:30:44They literally get engaged into this
- 1:30:46discussion of, you know, what happened
- 1:30:48in a world where skill and
- 1:30:51skill and unskill workers are
- 1:30:53complementary, for example.
- 1:30:55Right? And Ben Jones says, well, if you
- 1:30:57do that, then the role of human capital
- 1:30:59is going to be much larger.
- 1:31:02But then, you know, Caselli and Ciccone
- 1:31:04said, well, wait, wait. You need to be
- 1:31:06careful because then one needs to really
- 1:31:09think that whatever differences in wages
- 1:31:11that we see between skill and unskill
- 1:31:14workers are not
- 1:31:16at all connected to differences in
- 1:31:18technology.
- 1:31:20Because if they are, part of that is
- 1:31:22really differences in, you know, in TFP.
- 1:31:24And then at that point, the role of
- 1:31:26human capital can be as little as you
- 1:31:28want and as big as you want.
- 1:31:30And then there is a nice response from
- 1:31:32from Ben Jones to to this discussion
- 1:31:34that I think is worth for for the
- 1:31:36students here to to read. Kind of
- 1:31:39saying, okay, yes, we can consider on on
- 1:31:42on this front. But let's think really
- 1:31:44about how to do accounting in a world
- 1:31:46where there are all these
- 1:31:47complementarities in factor of
- 1:31:48production.
- 1:31:49So, I think everything is there to be to
- 1:31:51be written. The one thing that I want to
- 1:31:53mention is that once you go into the
- 1:31:55world where all these inputs are not
- 1:31:58perfect substitutes in production,
- 1:32:00the simple accounting
- 1:32:03uh tools that I have brought up
- 1:32:05cannot really be used really off the
- 1:32:08shelf. And I think a
- 1:32:11even more important question is, what's
- 1:32:12the elasticity of substitution between
- 1:32:14these factors?
- 1:32:15Okay, even if you're going to go that
- 1:32:17way.
- 1:32:18I you know, there is an active
- 1:32:19discussion in developed economies, in
- 1:32:21particular in the US, as of what those
- 1:32:22elasticities are.
- 1:32:25Um so, I think you know, there there are
- 1:32:27a lot of open questions.
- 1:32:29Uh unfortunately, I don't know the
- 1:32:31answer, but I think yes, this is a
- 1:32:33feature of the data that is potentially
- 1:32:34important. It's also important uh in
- 1:32:37terms of what Andres was asking of, you
- 1:32:39know, the choice of technology given a
- 1:32:41constraint set.
- 1:32:43So, you know, I'll I'll look forward to
- 1:32:45the papers that have will come up on
- 1:32:46this.
- 1:32:48I'm sorry, but I have to to uh cut off
- 1:32:50the conversation. Again, uh there will
- 1:32:53be the um TA session for Monday.
- 1:32:55Uh we want to thank uh Julieta. Um it
- 1:32:58was a very big crowd. Uh people are
- 1:33:00dropping off now, of course, but um
- 1:33:03uh one thing for students to know is
- 1:33:05that basically everybody who's teaching
- 1:33:07here is doing this out of the generosity
- 1:33:09of their
- 1:33:10their hearts. Uh I also want to thank uh
- 1:33:12Mandy and Kiersten one more time. Uh
- 1:33:14next week, we will have on a Thursday,
- 1:33:16Todd Schoellman will be discussing more
- 1:33:18about human capital. Uh so, some any
- 1:33:20questions about human capital, you can
- 1:33:22bring those to next week. And uh that'll
- 1:33:24be Thursday, and then on Friday, uh same
- 1:33:27time, will be uh Bertolt Herrendorf
- 1:33:30talking about structural transformation.
- 1:33:33Thank you all.
- 1:33:34Thank you.
- 1:33:35Thank you. Julieta, fantastic.
- 1:33:39Thanks, Doug. Thanks, Joel.
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