Essays in empirical microeconomics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2008.Includes bibliographical references.This thesis consists of three essays addressing open empirical questions in applied microeconomics. Chapter 1 attempts to quantify the impact of climate change on Indian agriculture. I use historical data on past yearly weather fluctuations and crop yields to measure the effect of these weather fluctuations on output, then use climate change prediction models to derive projections of the impact of future climate change on future productivity. I find that even moderate climate change could be seriously detrimental to productivity, with a consensus prediction for warming over the period 2010-2039 reducing productivity 4.5 to 9 percent. Chapter 2 provides a new tool for analysis of distributional, or quantile, effects in regression discontinuity (RD) models. RD has become increasingly popular over the last decade as a method of obtaining quasi experimental estimates of mean treatment effects. This paper extends the methodology to the measurement of quantile treatment effects. I provide simulation evidence on the effectiveness of the estimator and an empirical application to returns to compulsory schooling in the United Kingdom. Chapter 3, written jointly with Esther Duflo and Michael Greenstone, examines the impact of a water and sanitation intervention in Orissa, India, on health outcomes, in particular the monthly incidence of severe cases of diarrhea and malaria. The design of the intervention, in particular the fact that the water system is activated suddenly, unpredictably and simultaneously for all households in a given village, allow us to overcome several empirical challenges that have impeded credible estimation in the past. We find large effects: the arrival of services appears to reduce severe cases of diarrhea by as much as forty percent, with similar effects on severe cases of malaria. Furthermore, these effects appear to be persistent, as they continue to be apparent in the data after three and even five years.by Raymond P. Guiteras.Ph.D

The implications of three major new trials for the effect of water, sanitation and hygiene on childhood diarrhea and stunting: a consensus statement

BACKGROUND: Three large new trials of unprecedented scale and cost, which included novel factorial designs, have found no effect of basic water, sanitation and hygiene (WASH) interventions on childhood stunting, and only mixed effects on childhood diarrhea. Arriving at the inception of the United Nations' Sustainable Development Goals, and the bold new target of safely managed water, sanitation and hygiene for all by 2030, these results warrant the attention of researchers, policy-makers and practitioners. MAIN BODY: Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors. We judge these trials to have high internal validity, constituting good evidence that these specific interventions had no effect on childhood linear growth, and mixed effects on childhood diarrhea. These results suggest that, in settings such as these, more comprehensive or ambitious WASH interventions may be needed to achieve a major impact on child health. CONCLUSION: These results are important because such basic interventions are often deployed in low-income rural settings with the expectation of improving child health, although this is rarely the sole justification. Our view is that these three new trials do not show that WASH in general cannot influence child linear growth, but they do demonstrate that these specific interventions had no influence in settings where stunting remains an important public health challenge. We support a call for transformative WASH, in so much as it encapsulates the guiding principle that - in any context - a comprehensive package of WASH interventions is needed that is tailored to address the local exposure landscape and enteric disease burden

Productivity in Piece-Rate Labor Markets: Evidence from Rural Malawi

Piece-rate compensation is a common feature of developing country labor markets, but little is known about how piece-rate workers respond to incentives, or the tradeoffs that an employer faces when setting the terms of the contract. In a field experiment in rural Malawi, we hired casual day laborers at piece rates and collected detailed data on the quantity and quality of their output. Specifically, we use a simplified Becker-DeGroot-Marschak mechanism, which provides random variation in piece rates conditional on revealed reservation rates, to separately identify the effects of worker selection and incentives on output. We find a positive relationship between output quantity and the piece rate, and show that this is solely the result of the incentive effect, not selection. In addition, we randomized whether workers were subject to stringent quality monitoring. Monitoring led to higher quality output, at some cost to the quantity produced. However, workers do not demand higher compensation when monitored, and monitoring has no measurable effect on the quality of workers willing to work under a given piece rate. Together, the set of worker responses that we document lead the employer to prefer a contract that offers little surplus to the worker, consistent with an equilibrium in which workers have little bargaining power

Eliciting and Utilizing Willingness-to-Pay: Evidence from Field Trials in Northern Ghana

Using the Becker-DeGroot-Marschak (BDM) mechanism, we estimate the willingness-to-pay (WTP) for and impact of clean water technology through a field experiment in Ghana. Although WTP is low relative to the cost, demand is relatively inelastic at low prices. In the short-run, treatment effects are positive—the incidence of children’s diarrhea falls by one third—and consistent throughout the WTP distribution. After a year, usage has fallen, particularly for those with relatively low valuations. Strikingly, the long-run average treatment effect is negative for those with valuations below the median. Combining estimated treatment effects with individual willingness-to pay measures implies households’ valuations of health benefits are much smaller than those typically used by policymakers. Finally, we explore differences between BDM and take-it-or-leave-it valuations and make recommendations for effectively implementing BDM in the field

Social and Financial Incentives for Overcoming a Collective Action Problem

Addressing public health externalities often requires community-level collective action. Due to social norms, each person’s sanitation investment decisions may depend on the decisions of neighbors. We report on a cluster randomized controlled trial conducted with 19,000 households in rural Bangladesh where we grouped neighboring households and introduced (either financial or social recognition) rewards with a joint liability component for the group, or asked each group member to make a private or public pledge to maintain a hygienic latrine. The group financial reward has the strongest impact in the short term (3 months), inducing a 7.5-12.5 percentage point increase in hygienic latrine ownership, but this effect dissipates in the medium term (15 months). In contrast, the public commitment induced a 4.2-6.3 percentage point increase in hygienic latrine ownership in the short term, but this effect persists in the medium term. Non-financial social recognition or a private pledge has no detectable effect on sanitation investments

Social and Financial Incentives for Overcoming a Collective Action Problem

Addressing public health externalities often requires community-level collective action. Due to social norms, each person’s sanitation investment decisions may depend on the decisions of neighbors. We report on a cluster randomized controlled trial conducted with 19,000 households in rural Bangladesh where we grouped neighboring households and introduced (either financial or social recognition) rewards with a joint liability component for the group, or asked each group member to make a private or public pledge to maintain a hygienic latrine. The group financial reward has the strongest impact in the short term (3 months), inducing a 7.5-12.5 percentage point increase in hygienic latrine ownership, but this effect dissipates in the medium term (15 months). In contrast, the public commitment induced a 4.2-6.3 percentage point increase in hygienic latrine ownership in the short term, but this effect persists in the medium term. Non-financial social recognition or a private pledge has no detectable effect on sanitation investments

statacons: An SCons-based build tool for Stata

In this article, we present statacons, an SCons-based build tool for Stata. Because of the integration of Stata and Python in recent versions of Stata, we are able to adapt SCons for Stata workflows without the use of an external shell or extensive configuration. We discuss the usefulness of build tools generally, provide examples of the use of statacons in Stata workflows, present key elements of the syntax of statacons, and discuss extensions, alternatives, and limitations. We provide recommendations for collaborative workflows and, at the end of the article, installation instructions

statacons: An SCons-based build tool for Stata

In this article, we present statacons, an SCons-based build tool for Stata. Because of the integration of Stata and Python in recent versions of Stata, we are able to adapt SCons for Stata workflows without the use of an external shell or extensive configuration. We discuss the usefulness of build tools generally, provide examples of the use of statacons in Stata workflows, present key elements of the syntax of statacons, and discuss extensions, alternatives, and limitations. We provide recommendations for collaborative workflows and, at the end of the article, installation instructions

The Pursuit of Balance in Sequential Randomized Trials

In many randomized trials, subjects enter the sample sequentially. Because thecovariates for all units are not known in advance, standard methods of stratificationdo not apply. We describe and assess the method of DA-optimal sequential allocation(Atkinson, 1982) for balancing stratification covariates across treatment arms. Weprovide simulation evidence that the method can provide substantial improvementsin precision over commonly-employed alternatives. We also describe our experience implementing the method in a field trial of a clean water and handwashing intervention in Dhaka, Bangladesh, the first time the method has been used. We provide advice and software for future researchers

statacons: An SCons-based build tool for Stata

In this article, we present statacons, an SCons-based build tool for Stata. Because of the integration of Stata and Python in recent versions of Stata, we are able to adapt SCons for Stata workflows without the use of an external shell or extensive configuration. We discuss the usefulness of build tools generally, provide examples of the use of statacons in Stata workflows, present key elements of the syntax of statacons, and discuss extensions, alternatives, and limitations. We provide recommendations for collaborative workflows and, at the end of the article, installation instructions