duflo

My Conversation with Esther Duflo

Self-recommending if there ever was such a thing, here is the audio and transcript.  In addition to all of the expected topics, including gender in the economics profession, we even got around to Indian classical music and Bach cantatas (she prefers the latter).  Excerpt:

COWEN: Do you worry much that the RCT method — it centralizes authority in too few institutions? You need a certain amount of money. You need some managerial ability. You need connections abroad. It’s not like running regressions — everyone can do it on their PC. Is that, in some way, going to slow down science? You get more reliable results, but there’s much less competition of ideas, it seems.

DUFLO: I think it would be the case if we had not been mindful of this problem from the beginning. And it might still be the case to some extent. But I actually think that we’ve put a lot of effort in avoiding it to be the case.

When you take an organization like J-PAL, just in India we have 200 staff members. And we have, at any given time, 1,000 people running surveys. I say we, but these people are not running my project. These people are running the projects of dozens and dozens of researchers. When I started, I couldn’t have started without having the backing of my team because it was such a risky proposition that you needed to be able to easy risk capital kind of things.

But at this point, because of the infrastructure, it’s much more normal sense. People can get in with no funding of their own, in part because one of the things we are doing as a network is raising a lot of money to redistribute to other people widely. J-PAL has 400 researchers that are affiliated to it, or invited researchers, many of them quite, quite junior.

So that sort of mixture — it was very important to us, and I think we’ve been quite successful at making the tool marginally available. It’s never going to be like running a regression from your computer. But my philosophy is that if you have the drive and you’re willing to put in your own sweat equity, you can do it. And our students and many other students who are not at top institutions are doing it.

And:

COWEN: On the internet, there’s a photo of a teenage Esther Duflo — at least it looks like you — protesting against fascism in Russia on top of a tank, is it?

DUFLO: That was a bus, and it was me. It was me. So that was in 1991. This was not when I lived for one year there. I lived one year in ’93–’94. But this was in ’91. I had gone to Russia about every year since I was a teen to learn Russian. I happened to be there the summer where there was this putsch against Gorbachev. That summer…

And someone gave me that fashizm ne poletit placard and asked me to hold it. And I’m like, “Sure, I’m going to hold it.” So I’m holding my placard. We stayed there for a long time when things were happening. Next time I saw in the evening, my parents called me, “What are you doing?” Because it turned out that that image was on all the TVs in the world. [laughs] And that’s how I very briefly became the face of this revolution.

And:

COWEN: Does child-rearing in France strike you as more sensible than child-rearing in the United States?

DUFLO: Oh very much so, very much so.

COWEN: And why?

DUFLO: You know that book, Bringing Up Bébé?

COWEN: Yes.

DUFLO: I think she picked up on something which rings so true to me, which maybe is a marginal point about the US versus France. In France people are reasonably content to just go with the flow and do what everybody does. Every kid eats the same thing at 4:30, has dinner at the same time, has gone through the same experiences, learned the same songs, and everybody thinks they are totally free. But in fact, they are all on this pretty sensible railroad. And also, they don’t agonize about it.

In the US, child-rearing is one more occasion to make a statement about your identity. You’re the kind of mother that carries the baby, or you’re the kind of mother that puts the baby in a stroller. And somehow it almost can predict what you’re going to think about Donald Trump. That’s crazy. Some people are so concerned about what they do. Not only they feel that they have to invest a ton in their children, and they feel inadequate if they are not able to, but also, exactly what they do creates them as people.

In France that’s not there, and I think that makes everybody so much more laid back, children and adults.

Recommended throughout.

Esther Duflo reminiscenses

I first contacted Esther (and Abhijit) in 2006, when I wanted to write a New York Times column on their RCT work in India, specifically Hyderabad.  They were both extremely welcoming of my inquiries and did everything possible to give me a chance to observe their work up close.

I ended up traveling to Hyderabad, India, and spent a whole day with their RCT program in the field.  Annie Duflo, Esther’s sister, was gracious enough to travel with me around the city for an entire day, visiting the meetings where the women would show up to receive loans, and talking with the loan suppliers.  Overall I was astonished at how well-organized the work was, and how sophisticated the on-the-ground implementers were.  This was really work very carefully done.

Then, in 2013, seven years later, Banerjee and Duflo and co-authors Glennerster and Kinnan created a paper with the core results from the experiment, here is one version of the abstract:

This paper reports results from the randomized evaluation of a group lending microcredit program in Hyderabad, India. A lender worked in 52 randomly selected neighborhoods, leading to an 8.4 percentage point increase in takeup of microcredit. Small business investment and profits of pre-existing businesses increased, but consumption did not significantly increase. Durable goods expenditure increased, while “temptation goods” expenditure declined. We found no significant changes in health, education, or women’s empowerment. Two years later, after control areas had gained access to microcredit but households in treatment area had borrowed for longer and in larger amounts, very few significant differences persist.

Along with some (broadly consistent) results from Dean Karlan, this became one of the definitive papers on the effects of micro-credit.  It meant that micro-credit is OK, but not the cure for poverty.  That had a big subsequent impact on both policy and philanthropy.

You might have thought they would rest there, but no, they kept on looking at the data more deeply and over additional years, hoping to learn yet more from the experiment.  And just this last week, a new paper came out, modifying the earlier results, based on more years of data.  Here is the new abstract and paper (with Breza and Kinnan):

Can microcredit help unlock a poverty trap for some people by putting their businesses on a different trajectory? Could the small microcredit treatment effects often found for the average household mask important heterogeneity? In Hyderabad, India, we find that “gung ho entrepreneurs” (GEs), households who were already running a business before microfinance entered, show persistent benefits that increase over time. Six years later, the treated GEs own businesses that have 35% more assets and generate double the revenues as those in control neighborhoods. We find almost no effects on non-GE households. A model of technology choice in which talented entrepreneurs can access either a diminishing-returns technology, or a more productive technology with a fixed cost, generates dynamics matching the data. These results show that heterogeneity in entrepreneurial ability is important and persistent. For talented but low-wealth entrepreneurs, short-term access to credit can indeed facilitate escape from a poverty trap.

That is a pretty stunning extension of the original results, bravo to all hands involved!  Rust never sleeps, and in the hands of Banerjee and Duflo, neither does science.

The Nobel Prize in Economic Science Goes to Banerjee, Duflo, and Kremer

The Nobel Prize goes to Abhijit Banerjee, Esther Duflo and Michael Kremer (links to home pages) for field experiments in development economics. Esther Duflo was a John Bates Clark Medal winner, a MacArthur “genius” award winner, and is now the second woman to win the economics Nobel and by far the youngest person to ever win the economics Nobel (Arrow was the previous youngest winner!). Duflo and Banerjee are married so these are also the first spouses to win the economics Nobel although not the first spouses to win Nobel prizes–there was even one member of a Nobel prize winning spouse-couple who won the Nobel prize in economics. Can you name the spouses?

Michael Kremer wrote two of my favorite papers ever. The first is Patent Buyouts which you can find in my book Entrepreneurial Economics: Bright Ideas from the Dismal Science. The idea of a patent buyout is for the government to buy a patent and rip it up, opening the idea to the public domain. How much should the government pay? To decide this they can hold an auction. Anyone can bid in the auction but the winner receives the patent only say 10% of the time–the other 90% of the time the patent is bought by the government at the market price. The value of this procedure is that 90% of the time we get all the incentive properties of the patent without any of the monopoly costs. Thus, we eliminate the innovation tradeoff. Indeed, the government can even top the market price up by say 15% in order to increase the incentive to innovate. You might think the patent buyout idea is unrealistic. But in fact, Kremer went on to pioneer an important version of the idea, the Advance Market Commitment for Vaccines which was used to guarantee a market for the pneumococcal vaccine which has now been given to some 143 million children. Bill Gates was involved with governments in supporting the project.

My second Kremer paper is Population Growth and Technological Change: One Million B.C. to 1990. An economist examining one million years of the economy! I like to say that there are two views of humanity, people are stomachs or people are brains. In the people are stomachs view, more people means more eaters, more takers, less for everyone else. In the people are brains view, more people means more brains, more ideas, more for everyone else. The people are brains view is my view and Paul Romer’s view (ideas are nonrivalrous). Kremer tests the two views. He shows that over the long run economic growth increased with population growth. People are brains.

Oh, and can I add a third Kremer paper? The O-Ring Model of Development is a great and deep paper. (MRU video on the O-ring model).

The work for which the Nobel was given is for field experiments in development economics. Kremer began this area of research with randomized trials of educational policies in Kenya. Duflo and Banerjee then deepened and broadened the use of field experiments and in 2003 established the Poverty Action Lab which has been the nexus for field experiments in development economics carried on by hundreds of researchers around the world.

Much has been learned in field experiments about what does and also doesn’t work. In Incentives Work, Dufflo, Hanna and Ryan created a successful program to monitor and reduce teacher absenteeism in India, a problem that Michael Kremer had shown in Missing in Action was very serious with some 30% of teachers not showing up on a typical day. But when they tried to institute a similar program for nurses in Putting a Band-Aid on A Corpse the program was soon undermined by local politicians and “Eighteen months after its inception, the program had become completely ineffective.” Similarly, Banerjee, Duflo, Glennerster and Kinnan find that Microfinance is ok but no miracle (sorry fellow laureate Muhammad Yunus). A frustrating lesson has been the context dependent nature of results and the difficult of finding external validity. (Lant Pritchett in a critique of the “randomistas” argues that real development is based on macro-policy rather than micro-experiment. See also Bill Easterly on the success of the Washington Consensus.)

Duflo, Kremer and Robinson study How High Are Rates of Return to Fertilizer? Evidence from Field Experiments in Kenya. This is an especially interest piece of research because they find that rates of return are very high but that farmers don’t use much fertilizer. Why not? The reasons seem to have much more to do with behavioral biases than rationality. Some interventions help:

Our findings suggest that simple interventions that affect neither the cost of, nor the payoff to, fertilizer can substantially increase fertilizer use. In particular, offering farmers the option to buy fertilizer (at the full market price, but with free delivery) immediately after the harvest leads to an increase of at least 33 percent in the proportion of farmers using fertilizer, an effect comparable to that of a 50 percent reduction in the price of fertilizer (in contrast, there is no impact on fertilizer adoption of offering free delivery at the time fertilizer is actually needed for top dressing). This finding seems inconsistent with the idea that low adoption is due to low returns or credit constraints, and suggests there may be a role for non–fully rational behavior in explaining production decisions.

This is reminiscent of people in developed countries who don’t adjust their retirement savings rates to take advantage of employer matches. (A connection to Thaler’s work).

Duflo and Banerjee have conducted many of their field experiments in India and have looked at not just conventional questions of development economics but also at politics. In 1993, India introduced a constitutional rule that said that each state had to reserve a third of all positions as chair of village councils for women. In a series of papers, Duflo studies this natural experiment which involved randomization of villages with women chairs. In Women as Policy Makers (with Chattopadhyay) she finds that female politicians change the allocation of resources towards infrastructure of relevance to women. In Powerful Women (Beaman et al.) she finds that having once had a female village leader increases the prospects of future female leaders, i.e. exposure reduces bias.

Before Banerjee became a randomistas he was a theorist. His A Simple Model of Herd Behavior is also a favorite. The essence of the model can be explained in a simple example (from the paper). Suppose there are two restaurants A and B. The prior probability is that A is slightly more likely to be a better restaurant than B but in fact B is the better restaurant. People arrive at the restaurants in sequence and as they do they get a signal of which restaurant is better and they also see what choice the person in front of them made. Suppose the first person in line gets a signal that the better restaurant is A (contrary to fact). They choose A. The second person then gets a signal that the better restaurant is B. The second person in line also sees that the first person chose A, so they now know one signal is for A and one is for B and the prior is A so the weight of the evidence is for A—the second person also chooses restaurant A. The next person in line also gets the B signal but for the same reasons they also choose A. In fact, everyone chooses A even if 99 out of 100 signals are B. We get a herd. The sequential information structure means that the information is wasted. Thus, how information is distributed can make a huge difference to what happens. A lot of lessons here for tweeting and Facebook!

Banerjee is also the author of some original and key pieces on Indian economic history, most notably History, Institutions, and Economic Performance: The Legacy of Colonial Land Tenure Systems in India (with Iyer).

Duflo’s TED Talk. Previous Duflo posts; Kremer posts; Banerjee posts on MR.

Before last year’s Nobel announcement Tyler wrote:

I’ve never once gotten it right, at least not for exact timing, so my apologies to anyone I pick (sorry Bill Baumol!). Nonetheless this year I am in for Esther Duflo and Abihijit Banerjee, possibly with Michael Kremer, for randomized control trials in development economics.

As Tyler predicted he was wrong and also right. Thus, this years win is well-timed and well-deserved. Congratulations to all.

Banerjee and Duflo on poverty and food

It is an excellent piece, excerpt:

The poor often resist the wonderful plans we think up for them because they do not share our faith that those plans work, or work as well as we claim. We shouldn’t forget, too, that other things may be more important in their lives than food. Poor people in the developing world spend large amounts on weddings, dowries, and christenings. Part of the reason is probably that they don’t want to lose face, when the social custom is to spend a lot on those occasions. In South Africa, poor families often spend so lavishly on funerals that they skimp on food for months afterward.

And don’t underestimate the power of factors like boredom. Life can be quite dull in a village…

We often see the world of the poor as a land of missed opportunities and wonder why they don’t invest in what would really make their lives better. But the poor may well be more skeptical about supposed opportunities and the possibility of any radical change in their lives. They often behave as if they think that any change that is significant enough to be worth sacrificing for will simply take too long. This could explain why they focus on the here and now, on living their lives as pleasantly as possible and celebrating when occasion demands it.

Hat tip goes to half of the people I follow on Twitter.

Banerjee and Duflo defend RCT

The abstract is this:

Randomized experiments have become a popular tool in development economics research, and have been the subject of a number of criticisms. This paper reviews the recent literature, and discusses the strengths and limitations of this approach in theory and in practice. We argue that the main virtue of randomized experiments is that, due to the close collaboration between researchers and implementers, they allow the estimation of parameters that it would not otherwise be possible to evaluate. We discuss the concerns that have been raised regarding experiments, and generally conclude that while they are real, they are often not specific to experiments. We conclude by discussing the relationship between theory and experiments.

There are 39 additional pages, which I have yet to read.  The paper is here and hat tip goes to the essential Rachel Strohm.

Sunday assorted links

1. “As of Wednesday, women and men in Panama are under different quarantine schedules.

2. Banerjee and Duflo give their take.

3. On the decline of “Bridge Over Troubled Water.”  (I myself prefer “Cloudy,” among many other S&G songs.)

4. Does financial stress spur entrepreneurship?

5. “We find that firms that had more connections on the eve of the 1929 financial market crash have higher 10-year survival rates during the Great Depression. Consistent with a financing channel, we find that the results are particularly strong for small firms, private firms, cash-poor firms, and firms located in counties with high bank suspension rates during the crisis. Moreover, connections to cash-rich firms are stronger predictors of survival, overall and among financially constrained firms.”  Link here.

6. Is classical music becoming culturally more central under the lockdown?

7. 1957 flu memories, that was then this is now.

8. Roger Congleton model of the pandemic, the link downloads it rather than opening it up.

9. Maybe shaky as evidence, but this paper argues that thinking about coronavirus makes people more right-wing.

10. New site/model on estimating the number of infections.

11. How to do express loans for small businesses.

12. The impact on Native Americans.

The Advance Market Commitment

NBER: Ten years ago, donors committed $1.5 billion to a pilot Advance Market Commitment (AMC) to help purchase pneumococcal vaccine for low-income countries. The AMC aimed to encourage the development of such vaccines, ensure distribution to children in low-income countries, and pilot the AMC mechanism for possible future use. Three vaccines have been developed and more than 150 million children immunized, saving an estimated 700,000 lives. This paper reviews the economic logic behind AMCs, the experience with the pilot, and key issues for future AMCs.

That’s Kremer, Levin and Snyder. Definitely deserving of a Nobel and kudos to Bill and Melinda Gates for being early and major supporters.

Is it harder to become a top economist?

Mathis Lohaus writes to me:

Thanks for doing the Conversations. I greatly enjoyed Acemoglu, Duflo, and Banerjee in short succession after the Christmas break. Your question about “top-5 journals” and the bits about graduate training reminded of something I’ve had on my mind for a while now:

For the average PhD student, how hard is it to become a tenured economist — compared to 10, 20, 30, 40 … years ago? (And how about someone in the top 10% of talent/grit?)

Publication requirements have clearly become tougher in absolute terms. But how difficult is it to write a few “very good” papers in the first place? On twitter, people will sometimes say things like “oh, it must have been nice to get tenure back in 1997 based on 1 top article, which in turn was based on a simple regression with n = 60”. I wonder if that criticism is fair, because I imagine the learning curve for quantitative methods must have been challenging. And what about the formal models etc.? Surely those were always hard. (I vaguely remember a photo showing difficult comp exam questions…)

More broadly, early career scholars now have tons of data and inspiring research at their fingertips all the time. Also, nepotism and discrimination might be less powerful than in earlier decades…? On the other hand, you have to take into account that many more PhDs are awarded than ever before. I suspect that alone is a huge factor, but perhaps less acute if we focus only on people who “really, really want to stay in academia”.

A different way to ask the question: When would have been the best point in time to try to become an econ professor (in the USA)?

I would love to hear about your thoughts, and/or input from MR readers.

I always enjoy questions that somewhat answer themselves.  I would add these points:

1. The skills of networking and finding new data sets are increasingly important, all-important you might say, at least for those in the top tier of ability/effort.

2. Fundraising matters more too, because the project might cost a lot, RCTs being the extreme case here.

3. Managing your research team matters much more, and the average size of research team for influential work is much larger.  Once upon a time, three authors on a paper was considered slightly weird (the claim was one of them virtually always did nothing), now four is quite normal and the background research support is much higher as well.

Recently I was speaking to someone on the job market, wondering if he should be an academic.  I said: “In the old days you spent a higher percentage of your time doing economics.  Nowadays, you spend a higher percentage of your time managing a research team doing economics.  You hardly do economics at all.  So if you are mainly going to be a manager, why not manage for the higher rather than the lower salary?”

That was tongue in cheek of course.

On the bright side, learning today through the internet is so much easier.  For instance, I find YouTube a good way to learn/refresh on new ideas in econometrics, easier than just trying to crack the final published paper.

What else?

Most Popular Posts of 2019

Here are the top MR posts for 2019, as measured by landing pages. The most popular post was Tyler’s

1. How I practice at what I do

Alas, I don’t think that will help to create more Tylers. Coming in at number two was my post:

2. What is the Probability of a Nuclear War?

Other posts in the top five were 3. Pretty stunning data on dating from Tyler and my posts, 4. One of the Greatest Environmental Crimes of the 20th Century,and 5. The NYTimes is Woke.

My post on The Baumol Effect which introduced my new book Why are the Prices So Damned High (one of Mercatus’s most downloaded items ever) was number 6 and rounding out the top ten were a bunch from Tyler, including 7. Has anyone said this yet?, 8. What is wrong with social justice warriors?, 9. Reading and rabbit holes and my post Is Elon Musk Prepping for State Failure?.

Other big hits from me included

Tyler had some truly great posts in the last few days of 2019 including what I thought was the post of the year (and not just on MR!) Work on these things.

Also important were:

Happy holidays everyone!