Working Paper
David K. Evans and Fei Yuan. Working Paper. “Equivalent Years of Schooling: A Metric to Communicate Learning Gains in Concrete Terms”. Publisher's VersionAbstract
In the past decade, hundreds of impact evaluation studies have measured the learning outcomes of different education interventions in developing countries. The impact magnitudes are often reported in terms of “standard deviations,” making them difficult to communicate to policymakers beyond education specialists. This paper proposes two approaches to demonstrate the effectiveness of learning interventions, one in “equivalent years of schooling” (EYOS) and another in terms of 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 deviations 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 years 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 to better understand the potential benefits of increased learning.
David K. Evans and Fei Yuan. Working Paper. “Working Conditions of Teachers in Low- and Middle-Income Countries”.Abstract
Student learning levels in low- and middle-income countries are disappointingly low,
and analysis of the proximate causes often points to failures among teachers, such as a lack of content knowledge or high absenteeism. This review proposes that these metrics of teacher performance need to be viewed in the full context of teachers’ working conditions, for which there are few systematic data. We propose a framework for analyzing teachers’ working conditions, adapting Maslow’s Hierarchy of Needs. Then – drawing on an extensive quantitative and qualitative literature, including 133 Public Expenditure Reviews and Public Expenditure Tracking Surveys – we provide an overview of teachers’ working conditions across countries. We find that many education systems fail to provide basic working conditions for teachers to perform. This paper highlights a range of levers that could be explored to provide teachers with a conductive professional environment and improve teacher performance.
David K. Evans and Fei Yuan. Forthcoming. “How Big Are Effect Sizes in International Education Studies?” Educational Evaluation and Policy Analysis . Publisher's VersionAbstract

A growing literature measures the impact of education interventions in low- and middle-income countries on both access and learning outcomes. But how should one contextualize the size of impacts? This article provides the distribution of standardized effect sizes on learning and access from 234 studies in low- and middle-income countries. We identify a median effect size of 0.10 standard deviations on learning and 0.07 standard deviations on access among randomized controlled trials. Effect sizes are similar for quasi-experimental studies. Effects are larger and demonstrate higher variance for small-scale studies than for large-scale studies. The distribution of existing effects can help researchers and policymakers to situate new findings within current knowledge and design new studies with sufficient statistical power to identify effects.

David K. Evans, Fei Yuan, and Deon Filmer. 7/2022. “Teacher pay in Africa: Evidence from 15 countries.” World Development . Publisher's VersionAbstract
Pay levels for public sector workers—and especially teachers—are a constant source of controversy. In many countries in Sub-Saharan Africa, protests and strikes suggest that pay is low, while comparisons to average national income per capita suggest that it is high. This study presents data on teacher earnings from 15 African countries. The results suggest that in several (seven) countries, teachers’ monthly earnings are lower than other formal sector workers with comparable levels of education and experience. However, in all of those countries, teachers report working significantly fewer hours than other workers, such that hourly earnings are significantly lower for teachers in only one country. The study documents non-pecuniary benefits (such as medical insurance or a pension) for teachers relative to other workers: of the 13 country surveys that report non-pecuniary benefits, teachers are more likely to receive at least one benefit than other workers in 11. Teachers who report fewer hours are no more likely to report holding a second job, although teachers overall are nearly two times more likely to hold a second job than other workers. The study documents other characteristics of the teacher labor force across countries—e.g., mostly male but less so than other workers, mostly employed by the public sector. The study also documents within-country variation across types of teacher contracts—e.g., teachers on fixed term contracts make about 70 percent of teachers on permanent contracts, with wide variation across countries. The large heterogeneity in teacher earnings premia is not easily explained by observed characteristics of the countries’ economies or education systems. Nonetheless, after taking hours and non-pecuniary benefits into account, we find no evidence that teachers are systematically underpaid in this sample of countries.
David K. Evans and Fei Yuan. 2/2022. “What we learn about girls' education from interventions that don't focus on girls.” The World Bank Economic Review , 36, 1, Pp. 244-267. Publisher's VersionAbstract
What is the best way to improve access and learning outcomes for girls? This review brings together evidence from 267 educational interventions in 54 low- and middle-income countries – regardless of whether the interventions specifically target girls – and identifies their impacts on girls. To improve access and learning, general interventions deliver average gains for girls that are comparable to girl-targeted interventions. General interventions have similar impacts for girls as for boys. Taken together, these findings suggest that many educational gains for girls may be achieved through nontargeted programs. Many of the most effective interventions to improve access for girls relax household-level constraints (such as cash transfer programs), and many of the most effective interventions to improve learning for girls involve improving the pedagogy of teachers. Girl-targeted interventions may make the most sense when addressing constraints that are unique to, or most pronounced for, girls.
David K. Evans and Fei Yuan. 2018. Commentary: at the Bottom of the Pyramid, in Learning at the Bottom of the Pyramid: Science, measurement, and policy in low-income countries. Paris: UNESCO. Publisher's Version
Fei Yuan and Kevin P. Gallagher. 2018. “Greening Development Lending in the Americas: Trends and Determinants .” Ecological Economics, 154, Pp. 189-200. Publisher's VersionAbstract
Latin America and the Caribbean (LAC) faces a $110 billion-dollar annual gap in financing for climate change. This paper shows that development banks operating in the Americas are falling far short of playing the key role they need to assume in filling these gaps. According to our estimates, development banks provide just $7 billion per year in terms of green finance in general, and climate finance in particular is just $4.4 billion per year. A corresponding econometric analysis shows green financial flows tend to go to countries with higher human development scores and left of center governments, and derive from development banks where the majority of the shareholder governments have strong environmental performance in their home country.
Kevin P. Gallagher and Fei Yuan. 2017. “Standardizing Sustainable Development: A Comparison of Development Banks in the Americas.” Journal of Environment and Development , 26, 3, Pp. 243-271. Publisher's VersionAbstract
There is a sense of urgency in emerging market and developing countries in general, and Latin America in particular, for international development banks to generate a pipeline of infrastructure projects in order to reboot lagging economies and to meet broader sustainable development goals. In meeting those goals, it is important to also ensure that such efforts are socially inclusive and environmentally sustainable. To draw lessons for this new wave of development finance, this article conducts a comparative analysis of social and environmental safeguards across international development banks. We find a significant divergence in safeguard policy across development banks operating in the region, with Western-backed development banks requiring that borrowers harmonize to developed country standards to others such as China's and Brazil’s banks deferring to host country standards. On the basis of this research, we develop a framework that allows analysts to better empirically examine the impact of different safeguard regimes on environment, social, and development outcomes.