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 - 6 of 6
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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
Extending the School Day in Latin America and the Caribbean
(World Bank, Washington, DC, 2015-06)Countries throughout Latin America and the Caribbean are reforming their education systems with the view of adding more hours to the school day. This paper examines the existing evidence on the relationship between instructional time and student learning, and reviews 15 studies measuring the effects of longer school days. It draws on examples throughout the region to characterize differences in the implementation of extended school day programs, and provides one detailed case study and cost-effectiveness exercise (for Uruguay). While the evidence suggests positive impacts across a range of outcome variables, including gains in student learning, reductions in repetition and dropout, and reductions in teenage pregnancy, there is considerable heterogeneity across programs and studies. Even using the most optimistic impact estimates, a cost-effectiveness exercise suggests that there are likely many more cost-effective reforms to achieve similar effects. The paper concludes with a discussion of the implications for policy makers and practitioners considering an extension of the school day. -
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
Equivalent Years of Schooling: A Metric to Communicate Learning Gains in Concrete Terms
(World Bank, Washington, DC, 2019-02)In the past decade, hundreds of impact evaluation studies have measured the learning outcomes of education interventions in developing countries. The impact magnitudes are often reported in terms of "standard deviations," making them difficult to communicate to policy makers beyond education specialists. This paper proposes two approaches to demonstrate the effectiveness of learning interventions, one in "equivalent years of schooling" and another in the net present value of potential increased lifetime earnings. The results show that in a sample of low- and middle-income countries, one standard deviation gain in literacy skill is associated with between 4.7 and 6.8 additional years of schooling, depending on the estimation method. In other words, over the course of a business-as-usual school year, students learn between 0.15 and 0.21 standard deviation of literacy ability. Using that metric to translate the impact of interventions, a median structured pedagogy intervention increases learning by the equivalent of between 0.6 and 0.9 year of business-as-usual schooling. The results further show that even modest gains in standard deviations of learning -- if sustained over time -- may have sizeable impacts on individual earnings and poverty reduction, and that conversion into a non-education metric should help policy makers and non-specialists better understand the potential benefits of increased learning. -
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.