Analysis of statistical power reconciles drought-conflict results in Africa

Solomon M. Hsiang, Marshall Burke, Edward Miguel, Kyle C. Meng, Mark A. Cane
2016
African DevelopmentEnvironment and ClimateResearch Methodology
eScholarship UC item 77s421cd.pdf
Whether changes in climate substantially shape human conflict is a question of considerable recent interest to both academics and policymakers. Despite a substantial body of evidence for a strong association between climate and conflict, it remains widely claimed that large-sample empirical evidence linking climatic conditions and modern human conflict in Africa is mixed and thus any reported evidence for a strong association should be discounted. Theisen, Holterman, and Buhaug (henceforth THB) is one of the studies used to support this claim. Here we show that the results in THB are not inconsistent with earlier studies that report a substantial e ect of of climate on conflict. We demonstrate using power calculations and Monte Carlo simulations that even if a large association between climate and conflict existed in the data, the approach of THB would not be able to reliably distinguish this association from a null e ect, indicating that the approach taken by THB is statistically underpowered in this context. Therefore THB's analysis provides no basis for discarding earlier analyses and THB's conclusions drawn from this analysis overstate the extent to which they disagree with the literature. We also demonstrate that THB's stated advantage from using exceptionally high resolution data is unlikely to be realized in their analysis, since high resolution rainfall data was not actually collected in the majority conflict zones studied by THB. Although unremarked in the original analysis, the rainfall data in THB are interpolations of sparse and incomplete rainfall measurements.

Worms at work: Long-run impacts of a child health investment

Sarah Baird, Joan Hamory Hicks, Michael Kremer, and Edward Miguel
2016
African DevelopmentHealthEducation and Human CapitalResearch Methodology
Worms-at-Work 2016-07-12 FINAL CLEAN.pdf

This study estimates long-run impacts of a child health investment, exploiting community-wide experimental variation in school-based deworming. The program increased labor supply among men and education among women, with accompanying shifts in labor market specialization. Ten years after deworming treatment, men who were eligible as boys stay enrolled for more years of primary school, work 17% more hours each week, spend more time in non-agricultural self-employment, are more likely to hold manufacturing jobs, and miss one fewer meal per week. Women who were in treatment schools as girls are approximately one quarter more likely to have attended secondary school, halving the gender gap. They reallocate time from traditional agriculture into cash crops and non-agricultural self-employment. We estimate a conservative annualized financial internal rate of return to deworming of 32%, and show that mass deworming may generate more in future government revenue than it costs in subsidies.

Do Cash Transfers Improve Birth Outcomes? Evidence from Matched Vital Statistics, Social Security and Program Data

Verónica Amarante, Marco Manacorda, Edward Miguel, and Andrea Vigorito
2016
HealthEducation and Human CapitalOther
Do Cash Transfers Improve Birth Outcomes Evidence from Matched Vital Statistics and Program and Social Security Data.pdf

There is limited empirical evidence on whether cash transfers to poor pregnant women improve children's birth outcomes and potentially help weaken the cycle of intergenerational poverty. Using a unique array of program and social security administrative micro- data matched to longitudinal vital statistics in Uruguay, we estimate that participation in a generous social assistance program led to a sizable reduction in the incidence of low birthweight. The effect is due to faster intrauterine growth rather than longer gestational length. Our findings are consistent with improved maternal nutrition during pregnancy being a key driver of improved birthweight.

Education as Liberation?

Willa Friedman, Michael Kremer, Edward Miguel, and Rebecca Thornton
2016
African DevelopmentHealthEducation and Human CapitalPolitical Economy and Conflict
Ed-as-Lib 2015-09-27-FINAL.pdf
This paper studies the political and social impacts of increased education by utilizing a randomized girls’ merit scholarship programme in Kenya that raised test scores and secondary schooling. Consistent with the view that education empowers the disadvantaged to challenge authority, we find that the programme reduced the acceptance of domestic violence and political authority. Young women in programme schools also increased their objective political knowledge. We find that this rejection of the status quo did not translate into greater perceived political efficacy, community participation or voting intentions. Instead, there is suggestive evidence that the perceived legitimacy of political violence increased.

Healing the Wounds: Learning from Sierra Leone’s Post-war Institutional Reforms

Katherine Casey, Rachel Glennerster, and Edward Miguel
2016
African DevelopmentPolitical Economy and Conflict
w18368.pdf

While its recent history of civil war, chronic poverty and corrupt governance would cause many to dismiss Sierra Leone as a hopeless case, the country's economic and political performance over the last decade has defied expectations. We examine how several factors—including the legacy of war, ethnic diversity, decentralization and community-driven development (CDD)—have shaped local institutions and national political dynamics. The story that emerges is a nuanced one: war does not necessarily destroy the capacity for local collective action; ethnicity affects residential choice, but does not impede local public goods provision; while politics remain heavily ethnic, voters are willing to cross ethnic boundaries when they have better information about candidates; decentralization can work even where capacity is limited, although the results are mixed; and for all of its promise, CDD does not appear to transform local institutions nor social norms. All of these findings are somewhat “unexpected,” but they are quite positive in signaling that even one of the world’s poorest, most violent and ethnically diverse societies can overcome major challenges and progress towards meaningful economic and political development.