Category: Economics

The O-Ring Model of Development

Michael Kremer’s Nobel prize (with Duflo and Banerjee) reminded me of his important paper The O-Ring Theory of Development. I also rewatched my video on this paper from Tyler’s and my online class, Development Economics. This was from our powerpoint and iPad days so there are no fancy graphics but the video holds up! Mostly because it’s a great model with lots of interesting implications not just for development but also for the structure of the US economy. See also Jason Collins on Garett Jones’s extension of the model.

When can companies force change by standing up to foreign governments

From Jason Miklian, John E. Katsos, Benedicte Bull:

It’s easy to condemn firms for meek apologies — and to criticize the NBA and others as willing tools of the Chinese regime, “submitting to authoritarianism” to make a buck. However, our research suggests even when companies want to support global democracy and human rights, they find it much harder than anticipated and trap themselves in unenviable choices…

Our research has shown, time and again, how companies fail to live up to these lofty expectations [improving liberties and human rights]. It’s not for lack of trying. Instead, companies find the problems governments want them to solve are incredibly hard — and companies themselves suffer the political fallout when they can’t get things right.

And this:

Companies are most likely to deliver benefits when the measures they take are concrete, focused on specific goals and build on existing corporate expertise. These measures are more likely to affect change when companies join in collective actions by the business community that complement international political campaigns.

There is much more at the link, including discussions of China and South Africa.

Michael Kremer, Nobel laureate

To Alex’s excellent treatment I will add a short discussion of Kremer’s work on deworming (with co-authors, most of all Edward Miguel), here is one summary treatment:

Intestinal helminths—including hookworm, roundworm, whipworm, and schistosomiasis—infect more than one-quarter of the world’s population. Studies in which medical treatment is randomized at the individual level potentially doubly underestimate the benefits of treatment, missing externality benefits to the comparison group from reduced disease transmission, and therefore also underestimating benefits for the treatment group. We evaluate a Kenyan project in which school-based mass treatment with deworming drugs was randomly phased into schools, rather than to individuals, allowing estimation of overall program effects. The program reduced school absenteeism in treatment schools by one-quarter, and was far cheaper than alternative ways of boosting school participation. Deworming substantially improved health and school participation among untreated children in both treatment schools and neighboring schools, and these externalities are large enough to justify fully subsidizing treatment. Yet we do not find evidence that deworming improved academic test scores.

If you do not today have a worm, there is some chance you have Michael Kremer to thank!

With Blanchard, Kremer also has an excellent and these days somewhat neglected piece on central planning and complexity:

Under central planning, many firms relied on a single supplier for critical inputs. Transition has led to decentralized bargaining between suppliers and buyers. Under incomplete contracts or asymmetric information, bargaining may inefficiently break down, and if chains of production link many specialized producers, output will decline sharply. Mechanisms that mitigate these problems in the West, such as reputation, can only play a limited role in transition. The empirical evidence suggests that output has fallen farthest for the goods with the most complex production process, and that disorganization has been more important in the former Soviet Union than in Central Europe.

Kremer with co-authors also did excellent work on the benefits of school vouchers in Colombia.  And here is Kremer’s work on teacher incentives — incentives matter!  His early piece on wage inequality with Maskin, from 1996, was way ahead of its time.  And don’t forget his piece on peer effects and alcohol use: many college students think the others are drinking more than in fact they are, and publicizing the lower actual level of drinking can diminish alcohol abuse problems.  The Hajj has an impact on the views of its participants, and “… these results suggest that students become more empathetic with the social groups to which their roommates belong,.” link here.

And don’t forget his famous paper titled “Elephants.”  Under some assumptions, the government should buy up a large stock of ivory tusks, and dump them on the market strategically, to ruin the returns of elephant speculators at just the right time.  No one has ever worked through the issue before of how to stop speculation in such forbidden and undesirable commodities.

Michael Kremer has produced a truly amazing set of papers.

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.

Abhijit Banerjee reminiscenses

Abhijit and I were in the same first year class at Harvard, and I have two especially strong memories of him from that time.

First, he was always willing to help out those who were not as advanced in the class work as he was.  Furthermore, that was literally everyone else.  He was very generous with his time.

Second, when it came to the first-year Macro final (I don’t mean the comprehensive exams), Andy Abel wrote a problem with dynamic programming, which was Andy’s main research area at the time.  Abhijit showed that the supposed correct answer was in fact wrong, that the equilibrium upon testing was degenerate, and he re-solved the problem correctly, finding some multiple equilibria if I recall correctly, all more than what Abel had seen and Abel wrote the problem.  Abhijit got an A+ (Abel, to his credit, was not shy about reporting this).

One of my favorite Abhijit papers is “On Frequent Flyer Programs and other Loyalty-Inducing Economic Arrangements,” with Larry Summers.  I believe it was published QJE 1987, but somehow the jstor link does not show up from google searches.  This was one of the first papers to show how consumer loyalty programs could segment the market and have collusive effects.

Another favorite Abjihit paper of mine is his job market paper, “The Economics of Rumours,” later published in ReStud 1993.  Have you ever wondered “if this rumor is true, why haven’t I heard it before?”  Abhijit works through the logic of the model on that one, in a scintillating performance.  It turns out this paper is now highly relevant for analyzing information transmission through social media.

Abhijit is the clearest case I know of a brilliant theorist who decided the future was with empirical work — he was right.  Nonetheless his early theory papers are still worthy of attention.  When Abhijit went on the job market, his letter writers suggested he might someday win a Nobel Prize, so strong were his talents.  They were right, but I suspect they had no idea for what the prize in fact would turn out to be.

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.

The economic effects of private equity buyouts

We examine thousands of U.S. private equity (PE) buyouts from 1980 to 2013, a period that saw huge swings in credit market tightness and GDP growth. Our results show striking, systematic differences in the real-side effects of PE buyouts, depending on buyout type and external conditions. Employment at target firms shrinks 13% over two years in buyouts of publicly listed firms but expands 13% in buyouts of privately held firms, both relative to contemporaneous outcomes at control firms. Labor productivity rises 8% at targets over two years post buyout (again, relative to controls), with large gains for both public-to-private and private-to-private buyouts. Target productivity gains are larger yet for deals executed amidst tight credit conditions. A post-buyout widening of credit spreads or slowdown in GDP growth lowers employment growth at targets and sharply curtails productivity gains in public-to-private and divisional buyouts. Average earnings per worker fall by 1.7% at target firms after buyouts, largely erasing a pre-buyout wage premium relative to controls. Wage effects are also heterogeneous. In these and other respects, the economic effects of private equity vary greatly by buyout type and with external conditions.

That is from a new paper by Steven J. Davis, John Haltiwanger, Kyle Handley, Josh Lerner, Ben Lipsius, and Javier Miranda.  Via John Chamberlain.

My Conversation with Ben Westhoff

Truly an excellent episode, Ben is an author and journalist.  Here is the audio and transcript, covering most of all the opioid epidemic and rap music, but not only.

Here is one excerpt:

COWEN: But if so much fentanyl comes from China, and you can just send it through the mail, why doesn’t it spread automatically wherever it’s going to go? Is it some kind of recommender network? It wouldn’t seem that it’s a supply constraint. It’s more like someone told you about a restaurant they ate at last night.

WESTHOFF: It’s because the Mexican cartels are still really strongly in the trade. Even though it’s all made in China, much of it is trafficked through the cartels, who buy the precursors, the fentanyl ingredients, from China, make it the rest of the way. Then they send it through the border into the US.

You can get fentanyl in the mail from China, and many people do. It comes right to your door through the US Postal Service. But it takes a certain level of sophistication with the drug dealers to pull that off.

COWEN: It’s such a big life decision, and it’s shaped by this very small cost of getting a package from New Hampshire to Florida. What should we infer about human nature as a result of that? What’s your model of the human beings doing this stuff if those geographic differences really make the difference for whether or not you do this and destroy your life?

WESTHOFF: Well, everything is local, right? Not just politics. You’re influenced by the people around you and the relative costs. In St. Louis, it’s so incredibly cheap, like $5 to get some heroin, some fentanyl. I don’t know how it works in, say, New Hampshire, but I know in places like West Virginia, it’s still a primarily pill market. People don’t use powdered heroin, for example. For whatever reason, they prefer Oxycontin. So that has affected the market, too.

And:

COWEN: Did New Zealand do the right thing, legalizing so many synthetic drugs in 2013?

WESTHOFF: I absolutely think they did. It was an unprecedented thing. Now drugs like marijuana, cocaine, heroin, all the drugs you’ve heard of, are internationally banned. But what New Zealand did was it legalized these forms of synthetic marijuana. So synthetic marijuana has a really bad reputation. It goes by names like K2 and Spice, and it’s big in homeless populations. It’s causing huge problems in places like DC.

But if you make synthetic marijuana right, as this character in my book named Matt Bowden was doing in New Zealand, you can actually make it so it’s less toxic, so it’s somewhat safe. That’s what he did. They legalized these safer forms of it, and the overdose rate plummeted. Very shortly thereafter, however, they banned them again, and now deaths from synthetic marijuana in New Zealand have gone way up.

COWEN: And what about Portugal and Slovenia — their experiments in decriminalization? How have those gone?

WESTHOFF: By all accounts, they’ve been massive successes. Portugal had this huge problem with heroin, talking like one out of every 100 members of the population was touched by it, or something like that. And now those rates have gone way down.

In Slovenia, they have no fentanyl problem. They barely have an opioid problem. Their rates of AIDS and other diseases passed through needles have gone way down.

And on rap music:

COWEN: This question is maybe a little difficult to explain, but wherein lies the musical talent of hip-hop? If we look at Mozart, there’s melody, there’s harmony. If you listen to Stravinsky’s Rite of Spring, it’s something very specifically rhythmic, and the textures, and the organization of the blocks of sound. The poetry aside, what is it musically that accounts for the talent in rap music?

WESTHOFF: First of all, riding a beat, rapping, if you will, is extremely hard, and anyone who’s ever tried to do it will tell you. You have to have the right cadence. You have to have the right breath control, and it’s a talent. There’s also — this might sound trivial, but picking the right music to rap over.

So hip-hop, of course, is a genre that’s made up of other genres. In the beginning, it was disco records that people used. And then jazz, and then on and on. Rock records have been rapped over, even. But what song are you going to pick to use? And if someone has a good ear for a sound that goes with their style, that’s something you can’t teach.

And yes on overrated vs. underrated, you get Taylor Swift, Clint Eastwood, and Seinfeld, among others.  I highly recommend all of Ben’s books, but most of all his latest one Fentanyl, Inc.: How Rogue Chemists Are Creating the Deadliest Wave of the Opioid Epidemic.

Get Government Out of the Construction Business

USA Today: Nearly three years after city voters approved a $1.2 billion construction program over 10 years, the city has  yet to see the first building completed. Average per-apartment costs have zoomed more than $100,000 past prior predictions, the study by city Controller Ron Galperin finds.

…At an average cost of $531,373 per unit – with many apartments costing more than $600,000 each –  building costs of many of the homeless units will exceed the median sale price of a market-rate condominium.

…Prices rose dramatically because of higher-than-expected costs for items other than actual construction, such as consultants and financing. Those items comprise up to 40% of the cost of a project, the study found. By contrast, land acquisition costs averaged only 11% of the total costs.

Based on a recent audit of the program.

It’s absurd for a government to be building houses, a task for which it is manifestly unsuited. What the government should be doing is easing restrictions on building, improving public transportation which increases the supply of effective housing and dealing with any shortfalls by using housing vouchers.

California state taxes are too high and that is a problem

Among top-bracket California taxpayers, outward migration and behavioral responses by stayers together eroded 45.2% of the windfall tax revenues from the reform.

That is from a new NBER working paper by Joshua Rauh and Ryan J. Shyux.  Here is the full abstract:

Drawing on the universe of California income tax filings and the variation imposed by a 2012 tax increase of up to 3 percentage points for high-income households, we present new findings about the effects of personal income taxation on household location choice and pre-tax income. First, over and above baseline rates of taxpayer departure from California, an additional 0.8% of the California residential tax filing base whose 2012 income would have been in the new top tax bracket moved out from full-year residency of California in 2013, mostly to states with zero income tax. Second, to identify the impact of the California tax policy shift on the pre-tax earnings of high-income California residents, we use as a control group high-earning out-of-state taxpayers who persistently file as California non-residents. Using a differences-in-differences strategy paired with propensity score matching, we estimate an intensive margin elasticity of 2013 income with respect to the marginal net-of-tax rate of 2.5 to 3.3. Among top-bracket California taxpayers, outward migration and behavioral responses by stayers together eroded 45.2% of the windfall tax revenues from the reform.

You can file this one under Arthur Laffer: “these days definitely underrated.”

U.S. taxes are progressive

Here is the opener, by the excellent David Splinter:

U.S. federal taxes are progressive, as shown by Congressional Budget Office and Tax Policy Center estimates, with average tax rates increasing with income. In fact, the OECD (2011) estimated that the U.S. has the most progressive household taxes among developed countries. Moreover, the 2017 tax reform is expected to have little effect on overall tax progressivity (Tax Policy Center, 2017; Joint Committee on Taxation, 2019). But Saez and Zucman (2019) argue that average tax rates are nearly equal over the income distribution. To examine this claim, this paper compares other estimates of average tax rates by income group,all of which suggest a high degree of progressivity. Three issues are found to bias the average tax rates presented in Saez and Zucman (2019). After correcting for these issues, their estimates align more closely with other estimates that show U.S. taxes are progressive.

Here is the full (short) piece.  See also this Jason Furman thread.  Here is the Kopczuk thread.  There is a great deal of Twitter malpractice on this issue circulating these days.