Person:
Evans, David K.
Author Name Variants
Fields of Specialization
Education,
Social Development
Degrees
ORCID
Departments
Africa Chief Economist’s Office
Externally Hosted Work
Contact Information
Last updated
July 27, 2023
Biography
Bio: David is a Lead Economist in the Chief Economist's Office for the Africa Region of the World Bank. He coordinates impact evaluation work across sectors for the Africa Region. In the past, he worked as Senior Economist in the Human Development Department in the Latin America and the Caribbean Region of the World Bank, and as an economist designing and implementing impact evaluations in Africa. He has designed and implemented impact evaluations in agriculture, education, health, and social protection, in Brazil, the Gambia, Kenya, Mexico, Sierra Leone, and Tanzania. He has taught economic development at the Pardee RAND Graduate School of Public Policy, and he holds a Ph.D. in economics from Harvard University.
Publication Search Results
1 - 10 of 12
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Publication
Community-Based Conditional Cash Transfers in Tanzania : Results from a Randomized Trial
(Washington, DC: World Bank, 2014-03-04)Given the success of conditional cash transfer (CCT) programs elsewhere, in 2010 the Government of Tanzania rolled out a pilot CCT program in three districts. Its aim was to see if, using a model relying on communities to target beneficiaries and deliver payments, the program could improve outcomes for the poor the way centrally-run CCT programs have in other contexts. The program provided cash payments to poor households, but conditioned payments on complying with certain health and education requirements. Given scarce resources, the Government randomly selected 40 out of 80 eligible villages to receive the pilot program. Households in participating and comparison villages were broadly comparable at baseline. This report describes the program and the results of a rigorous, mixed methods impact evaluation. Two and a half years into the program, participating households were healthier and more educated. Health improvements due to the CCT program were greatest for the poorest half of households—the poorest of the poor. They experienced a half a day per month reduction in sick days on average, and poor children age 0-4 in particular had a full day per month reduction in sick days. In education, the program showed clear positive impacts on whether children had ever attended school and on whether they completed Standard 7. Households were also more likely to buy shoes for children, which can promote both health and school attendance. In response to the program, households also made investments to reduce risk: Participating households were much more likely to finance medical care with insurance and much more likely to purchase health insurance than were their comparison counterparts. The program did not significantly affect savings on aeverage, although it did increase non-bank savings amongst the poorest half of households. Participating households also invested in more livestock assets, which they used to create small enterprises. The program did not, however, have significant impacts on food consumption. On the whole, the results suggest that households focused on reducing risk and on improving their livelihoods rather than principally on increasing consumption. There is also evidence that the project had positive effects on community cohesion. -
Publication
The Permanent Input Hypothesis : The Case of Textbooks and (No) Student Learning in Sierra Leone
(World Bank Group, Washington, DC, 2014-09)A textbook provision program in Sierra Leone demonstrates how volatility in the flow of government-provided learning inputs to schools can induce storage of these inputs by school administrators to smooth future consumption. This process in turn leads to low current utilization of inputs for student learning. A randomized trial of a public program providing textbooks to primary schools had modest positive impacts on teacher behavior but no impacts on student performance. In many treatment schools, student access to textbooks did not actually increase because a large majority of the books were stored rather than distributed to students. At the same time, the propensity to save books was positively correlated with uncertainty on the part of head teachers regarding government transfers of books. The evidence suggests that schools that have high uncertainty with respect to future transfers are more likely to store a high proportion of current transfers. These results show that reducing uncertainty in school input flows could result in higher current input use for student learning. For effective program design, public policy programs must take forward-looking behavior among intermediate actors into account. -
Publication
The Next Wave of Deaths from Ebola?: The Impact of Health Care Worker Mortality
(World Bank, Washington, DC, 2015-07)The ongoing Ebola outbreak in West Africa has put a huge strain on already weak health systems. Ebola deaths have been disproportionately concentrated among health care workers, exacerbating existing skill shortages in Guinea, Liberia, and Sierra Leone in a way that will negatively affect the health of the populations even after Ebola has been eliminated. This paper combines data on cumulative health care worker deaths from Ebola, the stock of health care workers and mortality rates pre-Ebola, and coefficients that summarize the relationship between health care workers in a given country and rates of maternal, infant, and under-five mortality. The paper estimates how the loss of health care workers to Ebola will likely affect non-Ebola mortality even after the disease is eliminated. It then estimates the size of the resource gap that needs to be filled to avoid these deaths, and to reach the minimum thresholds of health coverage described in the Millennium Development Goals. Maternal mortality could increase by 38 percent in Guinea, 74 percent in Sierra Leone, and 111 percent in Liberia due to the reduction in health personnel caused by the epidemic. This translates to an additional 4,022 women dying per year across the three most affected countries. To avoid these deaths, 240 doctors, nurses, and midwives would need to be immediately hired across the three countries. This is a small fraction of the 43,565 doctors, nurses, and midwives that would need to be hired to achieve the adequate health coverage implied by the Millennium Development Goals. Substantial investment in health systems is urgently required not only to improve future epidemic preparedness, but also to limit the secondary health effects of the current epidemic owing to the depletion of the health workforce. -
Publication
Orphans and Ebola : Estimating the Secondary Impact of a Public Health Crisis
(World Bank Group, Washington, DC, 2015-02)The 2014 Ebola Virus Disease outbreak in West Africa is the largest to date by far. Ebola Virus Disease causes disproportionate mortality among the working-age population, resulting in far more mortality for parents of young children than other health crises. This paper combines data on the age distribution of current and projected mortality from Ebola with the fertility distribution of adults in Guinea, Liberia, and Sierra Leone, to estimate the likely impact of the epidemic on the number of orphans in these three countries. Using the latest mortality estimates (from February 11, 2015), it is estimated that more than 9,600 children have lost one or both parents to Ebola Virus Disease. The absolute numbers of orphans created by the Ebola epidemic are significant, but represent a small fraction (1.4 percent) of the existing orphan burden in the affected countries. Ebola is unlikely to increase the numbers of orphans beyond extended family networks' capacities to absorb them. Nonetheless, the pressures of caring for increased numbers of orphans may result in lower quality of care. These estimates should be used to guide policy to support family networks to improve the capacity to provide high quality care to orphans. -
Publication
Parental Human Capital and Effective School Management: Evidence from The Gambia
(World Bank, Washington, DC, 2015-04)Education systems in developing countries are often centrally managed in a top-down structure. In environments where schools have different needs and where localized information plays an important role, empowerment of the local community may be attractive, but low levels of human capital at the local level may offset gains from local information. This paper reports the results of a four-year, large-scale experiment that provided a grant and comprehensive school management training to principals, teachers, and community representatives in a set of schools. To separate the effect of the training from the grant, a second set of schools received the grant only with no training. A third set of schools served as a control group and received neither intervention. Each of 273 Gambian primary schools were randomized to one of the three groups. The program was implemented through the government education system. Three to four years into the program, the full intervention led to a 21 percent reduction in student absenteeism and a 23 percent reduction in teacher absenteeism, but produced no impact on student test scores. The effect of the full program on learning outcomes is strongly mediated by baseline local capacity, as measured by adult literacy. This result suggests that, in villages with high literacy, the program may yield gains on students learning outcomes. Receiving the grant alone had no impact on either test scores or student participation. -
Publication
The Impact of Distributing School Uniforms on Children’s Education in Kenya
(World Bank, Washington, DC, 2008-03-01)The authors evaluate the impact of an educational intervention, in which a Kenyan non-governmental organization distributes school uniforms to children in poor communities. The Nongovernmental organization (NGO) used a lottery to determine who would receive uniforms. Although compliance with the lottery was not perfect, we use winning the lottery as an instrumental variable to identify the impact of receiving a uniform. The authors find that giving a school uniform significantly reduces school absenteeism by 38 percent. Effects are much larger for poorer students who did not previously own a uniform: a 64 percent reduction in school absenteeism. Preliminary data suggest positive impacts of uniform distribution on test scores in core subjects. -
Publication
An Analysis of Clinical Knowledge, Absenteeism, and Availability of Resources for Maternal and Child Health: A Cross-Sectional Quality of Care Study in 10 African Countries
(World Bank, Washington, DC, 2020-10)This paper assesses the quality of health care across African countries based on health providers' clinical knowledge, their clinic attendance, and drug availability, with a focus on seven conditions accounting for a large share of child and maternal mortality: malaria, tuberculosis, diarrhea, pneumonia, diabetes, neonatal asphyxia, and postpartum hemorrhage. With nationally representative, cross-sectional data from 10 countries in Sub-Saharan Africa, collected using clinical vignettes, unannounced visits, and visual inspections of facilities, this study assesses whether health providers are available and have sufficient knowledge and means to diagnose and treat patients suffering from common conditions amenable to primary health care. The study draws on data from 8,061 primary and secondary care facilities in Kenya, Madagascar, Mozambique, Nigeria, Niger, Senegal, Sierra Leone, Tanzania, Togo, and Uganda, and 22,746 health workers. These data were gathered under the Service Delivery Indicators program. Across all conditions and countries, health care providers were able to correctly diagnose 64 percent of the clinical vignette cases, and in 45 percent of the cases, the treatment plan was aligned with the correct diagnosis. For diarrhea and pneumonia, two common causes of under-five deaths, 27 percent of the providers correctly diagnosed and prescribed the appropriate treatment for both conditions. On average, 70 percent of health workers were present in the facilities to provide care during facility hours when those workers were scheduled to be on duty. Taken together, the estimated likelihood that a facility has at least one staff present with competency and the key inputs required to provide child, neonatal, and maternity care that meets minimum quality standards is 14 percent. Poor clinical knowledge is a greater constraint in care readiness than drug availability or health workers' absenteeism in the 10 countries. However, the paper documents substantial heterogeneity across countries. -
Publication
Cash Transfers and Health: Evidence from Tanzania
(Published by Oxford University Press on behalf of the World Bank, 2019-06)How do cash transfers conditioned on health clinic visits and school attendance impact health-related outcomes? Examining the 2010 randomized introduction of a program in Tanzania, this paper finds nuanced impacts. An initial surge in clinic visits after 1.5 years—due to more visits by those already complying with program health conditions and by non-compliers—disappeared after 2.5 years, largely due to compliers reducing above-minimal visits. The study finds significant increases in take-up of health insurance and the likelihood of seeking treatment when ill. Health improvements were concentrated among children ages 0–5 years rather than the elderly, and took time to materialize; the study finds no improvements after 1.5 years, but 0.76 fewer sick days per month after 2.5 years, suggesting the importance of looking beyond short-term impacts. Reductions in sick days were largest in villages with more baseline health workers per capita, consistent with improvements being sensitive to capacity constraints. These results are robust to adjustments for multiple hypothesis testing. -
Publication
Cash Transfers and Health: Evidence from Tanzania
(World Bank, Washington, DC, 2016-11)How do conditional cash transfers impact health-related outcomes? This paper examines the 2010 randomized introduction of a program in Tanzania and finds nuanced impacts. An initial surge in clinic visits after 1.5 years -- due to more visits by those already complying with program health conditions and by non-compliers -- disappeared after 2.5 years, largely due to compliers reducing above-minimal visits. The study finds significant increases in take-up of health insurance and the likelihood of seeking treatment when ill. Health improvements were concentrated among children ages 0–5 years rather than the elderly, and took time to materialize; the study finds no improvements after 1.5 years, but 0.76 fewer sick days per month after 2.5 years, suggesting the importance of looking beyond short-term impacts. Reductions in sick days were largest in villages with more baseline health workers per capita, consistent with improvements being sensitive to capacity constraints. These results are robust to adjustments for multiple hypothesis testing. -
Publication
School Costs, Short-Run Participation, and Long-Run Outcomes: Evidence from Kenya
(World Bank, Washington, DC, 2018-04)Access to school has risen dramatically in recent decades, with large gains from reducing costs. Few studies report long-term impacts, however. This paper reports the impact of an educational intervention that reduced out-of-pocket schooling costs for children in poor communities in Kenya by providing school uniforms. The program used a lottery to determine who would receive a school uniform. Receiving a uniform reduced school absenteeism by 37 percent for the average student (7 percentage points) and by 55 percent for children who initially had no uniform (15 percentage points). Eight years after the program began, there is no evidence of sustained impact of the program on highest grade completed or primary school completion rates. A bounding exercise suggests no substantive positive, long-term impacts. These results contribute to a small literature that demonstrates the risk of fade-out of initial impacts of education investments.