Research

This study exploits a randomized school health intervention that provided deworming treatment to Kenyan children and utilizes longitudinal data to estimate impacts on economic outcomes up to 20 years later. The effective respondent tracking rate was 84%. Individuals who received 2 to 3 additional years of childhood deworming experience an increase of 14% in consumption expenditure, 13% in hourly earnings, 9% in non-agricultural work hours, and are 9% more likely to live in urban areas. Most effects are concentrated among males and older individuals. Given deworming's low cost, a conservative annualized social internal rate of return estimate is 37%.

Hamory, Joan, Edward Miguel, Michael Walker, Michael Kremer, and Sarah Baird. (2020). "Twenty Year Economic Impacts of Deworming", unpublished working paper.

The journal article is central to the research communication process. Guidelines for authors define what aspects of the research process should be made available to the community to evaluate, critique, reuse, and extend. Scientists recognize the value of transparency, openness, and reproducibility. Improvement of journal policies can help those values become more evident in daily practice and ultimately improve the public trust in science, and science itself.

B. A. Nosek, G. Alter, G. C. Banks, D. Borsboom, S. D. Bowman, S. J. Breckler, S. Buck, C. D. Chambers, G. Chin, G. Christensen, M. Contestabile, A. Dafoe, E. Eich, J. Freese, R. Glennerster, D. Goroff, D. P. Green, B. Hesse, M. Humphreys, J. Ishiyama, D. Karlan, A. Kraut, A. Lupia, P. Mabry, T. A. Madon, N. Malhotra, E. Mayo-Wilson, M. McNutt, E. Miguel, E. Levy Paluck, U. Simonsohn, C. Soderberg, B. A. Spellman, J. Turitto, G. VandenBos, S. Vazire, E. J. Wagenmakers, R. Wilson, and T. Yarkoni. “Promoting an Open Research Culture: Author guidelines for journals could help to promote transparency, openness, and reproducibility”, Science, 2015, 26 June 2015 348(6242): 1422-1425, 10.1126/science.aab2374.

Two articles published earlier this year in the International Journal of Epidemiology have re-ignited the debate over the World Health Organization’s long-held recommendation of mass-treatment of intestinal helminths in endemic areas. In this note, we discuss the content and relevance of these articles to the policy debate, and review the broader research literature on the educational and economic impacts of deworming. We conclude that existing evidence still indicates that mass deworming is a cost-effective health investment for governments in low-income countries where worm infections are widespread.

Hicks, Joan Hamory, Michael Kremer, and Edward Miguel. “The Case of Mass Treatment of Intestinal Helminths in Endemic Areas”, PLOS Neglected Tropical Diseases, 2015, 9(10): e0004214. 10.1371/journal.pntd.0004214.

Ethnic favoritism is seen as antithetical to development. This paper provides credible quantification of the extent of ethnic favoritism using data on road building in Kenyan districts across the 1963-2011 period. Guided by a model it then examines whether the transition in and out of democracy under the same president constrains or exacerbates ethnic favoritism. Across the 1963 to 2011 period, we …find strong evidence of ethnic favoritism: districts that share the ethnicity of the president receive twice as much expenditure on roads and have four times the length of paved roads built. This favoritism disappears during periods of democracy.

Burgess, Robin, Remi Jedwab, Edward Miguel, Ameet Morjaria, and Gerard Padró i Miquel. 2015. "The Value of Democracy: Evidence from Road Building in Kenya." 2015, American Economic Review, 105(6): 1817-1851, 10.1257/aer.20131031.

The impact of armed conflict on the environment is of major public policy importance. We use a geographically disaggregated dataset of civil war violence together with satellite imagery of land cover to test whether war facilitated or prevented forest loss in Sierra Leone. The conflict data set allows us to establish where rebel groups were stationed and where battles and attacks occurred. The satellite data enables to us to monitor the change in forest cover (total, primary, and secondary) in all of Sierra Leone's 151 chiefdoms, between 1990 (prior to the war) and 2000 (just prior to its end). The results suggest that conflict in Sierra Leone acted as a brake on local deforestation: conflict-ridden areas experienced significantly less forest loss relative to their more conflict-free counterparts.

Burgess, Robin, Edward Miguel, and Charlotte Stanton. (2015). "War and deforestation in Sierra Leone", Environmental Research Letters, 10 (2015) 095014.

In a study of the  effect  of civil war  exposure on local  collective action outcomes in Sierra Leone,  Bellows and Miguel (2009) employ a coefficient stability approach to assess the importance of omitted variable bias building on Altonji et al. (2005a). Here  we  clarify  the econometric assumptions underlying Bellows and  Miguel (2009), and  extend their analysis using data on  dependent variable reliability ratios and  the method developed in Oster (2015).

Gonzalez, Felipe and Edward Miguel. 2015. "War and Local Collective Action in Sierra Leone: A Comment on the Use of Coefficient Stability Approaches." 2015, Journal of Public Economics, 128: 30-33, 10.1016/j.jpubeco.2015.05.004.

We discuss how evidence and theory can be combined to provide insight on the appropriate subsidy level for health products, focusing on the specific case of deworming. Although intestinal worm infections can be treated using safe, low-cost drugs, some have challenged the view that mass school-based deworming should be a policy priority. We review well-identified research which both uses experimental or quasiexperimental methods to demonstrate causal relationships and adequately accounts for epidemiological externalities from deworming treatment, including studies of deworming campaigns in the Southern United States, Kenya, and Uganda. The existing evidence shows consistent positive impacts on school participation in the short run and on academic test scores, employment, and income in the long run, while suggesting that most parents will not pay for deworming treatment that is not fully subsidized. There is also evidence for a fiscal externality through higher future tax revenue, which may exceed the cost of the program. Our analysis suggests that the economic benefits of school-based deworming programs are likely to exceed their costs in places where worm infestations are endemic. This would likely be the case even if the benefits were only a fraction of estimates in the existing literature.

Amrita Ahuja, Sarah Baird, Joan Hamory Hicks, Michael Kremer, Edward Miguel, and Shawn Powers. (2015). "When Should Governments Subsidize Health? The Case of Mass Deworming", World Bank Economic Review, 10.1093/wber/lhv008.

We survey recent progress toward research transparency in the social sciences and make the case for standards and practices that help realign scholarly incentives with scholarly values. There is growing appreciation for the advantages of experimentation in the social sciences, but accompanying these changes is a growing sense that incentives, norms, and institutions under which social science operates undermine gains from improved research design. We describe promising, bottom-up innovations in the social sciences, including the three core practices of: disclosure; registration and preanalysis plans; and open data and materials. We also assess common objections to the move toward greater transparency, and argue that new practices need to be implemented in a way that does not stifle creativity or create excess burden. [Link to abstract]      [Link to PDF reprint]      [Link to full text]

E. Miguel, C. Camerer, K. Casey, J. Cohen, K. M. Esterling, A. Gerber, R. Glennerster, D. P. Green, M. Humphreys, G. Imbens, D. Laitin, T. Madon, L. Nelson, B. A. Nosek, M. Petersen, R. Sedlmayr, J. P. Simmons, U. Simonsohn, M. Van der Laan. 2014. "Promoting Transparency in Social Science Research." Science, 10.1126/science.1245317.

A comment by Buhaug et al. attributes disagreement between our recent analyses and their review articles to biased decisions in our meta-analysis and a difference of opinion regarding statistical approaches. The claim is false. Buhaug et al.’s alteration of our metaanalysis misrepresents findings in the literature, makes statistical errors, misclassifies multiple studies, makes coding errors, and suppresses the display of results that are consistent with our original analysis. We correct these mistakes and obtain findings in line with our original results, even when we use the study selection criteria proposed by Buhaug et al. We conclude that there is no evidence in the data supporting the claims raised in Buhaug et al.

Hsiang, Solomon M., Marshall Burke, and Edward Miguel. (2014). "Reconciling climate-conflict meta-analyses: reply to Buhaug et al.", Climatic Change, DOI 10.1007/s10584-014-1276-z.

Cane, Mark A., Marshall Burke, Solomon M. Hsiang, David B. Lobell, Kyle C. Meng, Edward Miguel, Shanker Satyanath, “Temperature and violence”, Nature Climate Change, 2014, 4, 234-235, 10.1038/nclimate2171.

We combine data from a randomized evaluation and a laboratory experiment to measure the causal impact of human capital on respect for earned property rights, a component of social preferences with important implications for economic growth and development. We find that higher academic achievement reduces the willingness of young Kenyan women to appropriate others' labor income, and shifts players toward a 50-50 split norm in a modified dictator game. This study demonstrates that education may have long-run impacts on social preferences, norms and institutions beyond the human capital directly produced.

Jakiela, Pamela, Edward Miguel, and Vera L. te Velde. 2014. "You've Earned It: Estimating the Impact of Human Capital on Social Preferences," Experimental Economics, 10.1007/s10683-014-9409-9.