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 "Twenty Year Economic Impacts of Deworming", unpublished working paper.

This study uses rainfall variation to estimate the impact of income shocks on murder in rural Tanzania. Extreme rainfall (drought or flood) leads to a large increase in the murder of "witches"--typically elderly women killed by relatives--but not other murders. The findings provide novel evidence on the role of income shocks in causing violent crime, and religious violence in particular.

Miguel, Edward. 2005. "Poverty and Witch Killing." Review of Economic Studies 72 (4): 1153-1172.

Social scientists studying entrepreneurship have emphasized three distinct sets of variables: the institutional environment, sociological variables, and personal and psychological characteristics. We are conducting surveys in five large developing and transition economies to better understand entrepreneurship. In this short paper, using over 2,000 interviews from a pilot study in Russia, we find evidence that the three sets of variables matter: perceptions of the local institutional environment, social network effects, and individual characteristics are all important in determining entrepreneurial behavior.

Djankov, Simeon, Edward Miguel, Yingyi Qian, Gerard Roland, and Ekaterina Zhuravskaya. 2005. "Who are Russia's Entrepreneurs?." Journal of the European Economic Association 3 (2-3): 587-597.

Estimating the impact of economic conditions on the likelihood of civil conflict is difficult because of endogeneity and omitted variable bias. We use rainfall variation as an instrumental variable for economic growth in 41 African countries during 1981-99. Growth is strongly negatively related to civil conflict: a negative growth shock of five percentage points increases the likelihood of conflict by one?half the following year. We attempt to rule out other channels through which rainfall may affect conflict. Surprisingly, the impact of growth shocks on conflict is not significantly different in richer, more democratic, or more ethnically diverse countries.

Miguel, Edward, Shanker Satyanath, and Ernest Sergenti. 2004. "Economic Shocks and Civil Conflict: An Instrumental Variables Approach." Journal of Political Economy 112 (4): 725-753.

This article examines how government policies affect ethnic relations by comparing outcomes across two nearby districts, one in Kenya and one in Tanzania, using colonial-era boundary placement as a "natural experiment." Despite similar geography and historical legacies, governments in Kenya and Tanzania have followed radically different language, education, and local institutional policies, with Tanzania consistently pursuing more serious nation building. The evidence suggests that nation building has allowed diverse communities in rural Tanzania to achieve considerably better local public goods outcomes than diverse communities in Kenya. To illustrate, while Kenyan communities at mean levels of diversity have 25 percent less local school funding than homogeneous communities on average, the comparable figure in the Tanzanian district is near zero. The Kenya-Tanzania comparison provides empirical evidence that serious reforms can ameliorate social divisions and suggests that nation-building should take a place on policy agendas, especially in Africa.

Miguel, Edward. 2004. "Tribe or Nation? Nation Building and Public Goods in Kenya Versus Tanzania." World Politics 56 (3): 327-362.

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.

Miguel, Edward, and Michael Kremer. 2004. "Worms: Identifying Impacts on Education and Health in the Presence of Treatment Externalities." Econometrica 72 (1): 159-217.

Miguel, Edward. 2003. "Comment on: Social Capital and Growth." Journal of Monetary Economics 50: 195-198.

OBJECTIVE: To report on the haemoglobin concentrations and prevalence of anaemia in schoolchildren in eight countries in Africa and Asia. DESIGN: Blood samples were collected during surveys of the health of schoolchildren as a part of programmes to develop school-based health services. SETTING: Rural schools in Ghana, Indonesia, Kenya, Malawi, Mali, Mozambique, Tanzania and Vietnam. SUBJECTS: Nearly 14 000 children enrolled in basic education in three age ranges (7±11 years, 12±14 years and ≥15 years) which reflect the new UNICEF/WHO thresholds to define anaemia. RESULTS: Anaemia was found to be a severe public health problem (defined as .40% anaemic) in five African countries for children aged 7±11 years and in four of the same countries for children aged 12±14 years. Anaemia was not a public health problem in the children studied in the two Asian countries. More boys than girls were anaemic, and children who enrolled late in school were more likely to be anaemic than children who enrolled closer to the correct age. The implications of the four new thresholds defining anaemia for school-age children are examined. CONCLUSIONS: Anaemia is a significant problem in schoolchildren in sub-Saharan Africa. School-based health services which provide treatments for simple conditions that cause blood loss, such as worms, followed by...

Hall, Andrew, Emily Bobrow, Simon Brooker, Matthew Jukes, Kate Nokes, Jane Lambo, Helen Guyatt, Don Bundy, Sam Adjei, Su-Tung Wen, Satoto, Hertanto Subagio, Mohammed Zen Rafiluddin, Ted Miguel, Sylvie Moulin, Joseph de Graft Johnson, Mary Mukaka, Nathalie Roschnik, Moussa Sacko, Anna Zacher, Bonifacio Mahumane, Charles Kihamia, Lillian Mwanri, Simon Tatala, Nicholas Lwambo, Julius Siza, Le Nguyen Bao Khanh, Ha Huy Khoi, and Nguyen Duy Toan. 2001. "Anaemia in Schoolchildren in Eight Countries in Africa and Asia." Public Health Nutrition 4(3): 749-756.

Data from 46 schools in western Kenya were used to investigate the performance of school-based questionnaires, on reported blood in stool and water-contact patterns, as indicators of the prevalence of human infection with Schistosoma mansoni. Prevalence of infection was associated with the prevalence of self-reported blood in stool, recent history of swimming and recent history of fishing. It was shown that use of a threshold of 30% of subjects reporting blood in stool would identify 42.9% of the `high-prevalence’ schools (i.e. prevalence ≥ 50%) and 87.5% of the `low-prevalence’ schools (i.e. prevalence < 50%). A threshold of 25% reporting swimming would identify 57.1% and 93.7% of the high- and low-prevalence schools, respectively. Blood in stool appears to be too coarse an indicator to identify schools for mass treatment correctly. Although the use of multiple questions improved the diagnostic performance of the questionnaire in identifying the high-prevalence schools, it was unclear how questions can best be combined in other settings. However, there is a direct relationship between prevalence of S. mansoni infection and distance of the school from the lakeshore; analysis indicated that use of a threshold of 5 km...

Brooker, Simon, Edward A. Miguel, Polycarp Waswa, Robert Namunyu, Sylvie Moulin, Helen Guyatt, and Donald A.P. Bundy. 2001. "The Potential of Rapid Screening Methods for Intestinal Schistosomiasis in Western Kenya." Annals of Tropical Medicine & Parasitology 95(4): 343-351.

OBJECTIVE: To describe the patterns of single and multiple helminth infection in school children from Busia District, Kenya. DESIGN: A cross-sectional school survey using a randomly selected sample, forming part of an evaluation study of an ongoing deworming project. SETTING: Budalangi and Funyula divisions of Busia District, Western Province, Kenya. SUBJECTS: One thousand seven hundred and thirty eight school children aged 8-20 years randomly selected from those enrolled in standards 3-8 in 25 randomly selected primary schools. RESULTS: Overall, 91.7% of children were infected with either hookworm, Ascaris lumbricoides, Trichuris trichiura or Schistosoma mansoni. Infection prevalence of each species varied considerably among schools, being most marked for  S. mansoni, where prevalence was highest in lakeshore schools. Children were typically infected with two or more species of helminth. Infection intensity of each geohelminth species was higher in school children infected with multiple species than in school children with single species infections, and intensity increased with the number of concurrent infections. CONCLUSION: Helminth infections are exceptionally common among school children in Busia district, thus confirming the good sense of the school-based approach adopted by the control programme. The study also shows that there is an association between concurrent infection and the intensity of infection, which may have...

Brooker, Simon, Edward A. Miguel, Sylvie Moulin, Alfred I. Louba, Donald A.P. Bundy, and Michael Kremer. 2000. "Epidemiology of Single and Multiple Species of Helminth Infections Among School Children in Busia District, Kenya." East African Medical Journal 77(3): 157-161.