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.