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
January 31, 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 37
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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
Cash Transfers and Temptation Goods : A Review of Global Evidence
(World Bank, Washington, DC, 2014-05)Cash transfers have been demonstrated to improve education and health outcomes and alleviate poverty in various contexts. However, policy makers and others often express concern that poor households will use transfers to buy alcohol, tobacco, or other "temptation goods." The income effect of transfers will increase expenditures if alcohol and tobacco are normal goods, but this may be offset by other effects, including the substitution effect, the effect of social messaging about the appropriate use of transfers, and the effect of shifting dynamics in intra-household bargaining. The net effect is ambiguous. This paper reviews 19 studies with quantitative evidence on the impact of cash transfers on temptation goods, as well as 11 studies that surveyed the number of respondents who reported they used transfers for temptation goods. Almost without exception, studies find either no significant impact or a significant negative impact of transfers on temptation goods. In the only (two, non-experimental) studies with positive significant impacts, the magnitude is small. This result is supported by data from Latin America, Africa, and Asia. A growing number of studies from a range of contexts therefore indicate that concerns about the use of cash transfers for alcohol and tobacco consumption are unfounded. -
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
Cost-Effectiveness Measurement in Development : Accounting for Local Costs and Noisy Impacts
(World Bank Group, Washington, DC, 2014-09)As evidence from rigorous impact evaluations grows in development, there have been more calls to complement impact evaluation analysis with cost analysis, so that policy makers can make investment decisions based on costs as well as impacts. This paper discusses important considerations for implementing cost-effectiveness analysis in the policy making process. The analysis is applied in the context of education interventions, although the findings generalize to other areas. First, the paper demonstrates a systematic method for characterizing the sensitivity of impact estimates. Second, the concept of context-specificity is applied to cost measurement: program costs vary greatly across contexts -- both within and across countries -- and with program complexity. The paper shows how adapting a single cost ingredient across settings dramatically shifts cost-effectiveness measures. Third, the paper provides evidence that interventions with fewer beneficiaries tend to have higher per-beneficiary costs, resulting in potential cost overestimates when extrapolating to large-scale applications. At the same time, recall bias may result in cost underestimates. The paper also discusses other challenges in measuring and extrapolating cost-effectiveness measures. For cost-effectiveness analysis to be useful, policy makers will require detailed, comparable, and timely cost reporting, as well as significant effort to ensure costs are relevant to the local environment. -
Publication
What Really Works to Improve Learning in Developing Countries?: An Analysis of Divergent Findings in Systematic Reviews
(World Bank Group, Washington, DC, 2015-02)In the past two years alone, at least six systematic reviews or meta-analyses have examined the interventions that improve learning outcomes in low- and middle-income countries. However, these reviews have sometimes reached starkly different conclusions: reviews, in turn, recommend information technology, interventions that provide information about school quality, or even basic infrastructure (such as desks) to achieve the greatest improvements in student learning. This paper demonstrates that these divergent conclusions are largely driven by differences in the samples of research incorporated by each review. The top recommendations in a given review are often driven by the results of evaluations not included in other reviews. Of 227 studies with student learning results, the most inclusive review incorporates less than half of the total studies. Variance in classification also plays a role. Across the reviews, the three classes of programs that are recommended with some consistency (albeit under different names) are pedagogical interventions (including computer-assisted learning) that tailor teaching to student skills; repeated teacher training interventions, often linked to another pedagogical intervention; and improving accountability through contracts or performance incentives, at least in certain contexts. Future reviews will be most useful if they combine narrative review with meta-analysis, conduct more exhaustive searches, and maintain low aggregation of intervention categories. -
Publication
Africa's Pulse, April 2015
(Washington, DC: World Bank, 2015-04)Africa’s Pulse is a biannual publication containing an analysis of the near-term macro-economic outlook for the region. It also includes a section focusing on a topic that represents a particular development challenges for the continent. It is produced by the Office of the Chief Economist for the Africa Region.This issue is an analysis of issues shaping Africa's economic future. Growth remains stable in Sub-Saharan Africa. Some countries are seeing a slowdown, but the region's economic prospects remain broadly favorable. External risks of higher global financial market volatility and lower growth in emerging market economies weigh on the downside. In several Sub-Saharan African countries, large budgetary imbalances are a source of vulnerability to exogenous shocks and underscore the need for rebuilding fiscal buffers in these countries. The Ebola outbreak is exacting a heavy human and economic toll on affected countries and, if not rapidly contained, the risk of wider contagion grows. Without a scale-up of effective interventions, growth would slow markedly not only in the core countries (Guinea, Liberia, and Sierra Leone), but also in the sub region as transportation, cross-border trade, and supply chains are severely disrupted. In Sub-Saharan Africa, growth in agriculture and services is more effective at reducing poverty than growth in industry. Structural transformation has a role to play in accelerating poverty reduction in Sub-Saharan Africa. Increasing agricultural productivity will be critical to fostering structural transformation. Boosting rural income diversification can facilitate this transformation, as well. Investments in rural public goods and services (for example, education, health, rural roads, electricity and ICT), including in small towns, will be conducive to lifting productivity in the rural economy. Although Sub-Saharan Africa's pattern of growth has largely bypassed manufacturing, growing the region's manufacturing base, especially by improving its fundamentals, lower transport cost, cheaper and more reliable power, and a more educated labor force, will benefit all sectors. -
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
Why Do Students Learn so Little?: Seeking Answers Inside Haiti's Classrooms
(World Bank, Washington, DC, 2015-05)The Haitian education system made substantial improvements in access over the last decade, such that today the majority of Haiti’s children are in school. Despite improvements, the primary education system is highly inefficient: children start primary school 2 years late on average, and fewer than 60 percent will reach the last grade of the cycle. At each school, classroom observations were conducted using the Stallings Classroom Snapshot instrument, and questions about the school calendar and daily schedule asked. The results provide a representative picture of class time and teacher classroom practice in the Nord and Nord Est departments, and while not representative of Haiti as a whole, do provide a starting point for better understanding the major constraint to achieving a high-quality education for all children: the quality of teacher instruction. Section two describes the sample of schools and the stallings instrument; sections three and four present the main results of the classroom observations on teacher time use and pedagogical practices; section five provides estimates of overall class time that students receive; and section six concludes. -
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
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.