In this paper I demonstrate, both theoretically and empirically, that the interpretation of regression estimates of between-group differences in economic outcomes depends on the relative sizes of subpopulations under study. When the disadvantaged group is small, regression estimates are similar...

We exploit exogenous variation in the risk of waterborne disease created by implementation of a major water reform in Mexico in 1991 to investigate impacts of infant exposure on indicators of cognitive development and academic achievement in late childhood. We estimate that a one standard...

Using administrative data on schools in England, we estimate an education production model of cognitive skills at the end of secondary school. We provide empirical evidence of selfproductivity of skills and of complementarity between secondary school inputs and skills at the end of primary...

In this paper I demonstrate, both theoretically and empirically, that the interpretation of regression estimates of between-group differences in economic outcomes depends on the relative sizes of subpopulations under study. When the disadvantaged group is small, regression estimates are similar...

In the past 15 years, four-year-olds' enrollment in state-funded pre-kindergarten in the United States has doubled, and advocates have pushed for further expansion. Although research has shown that pre-K programs can have important benefits, most existing studies have focused on small or...

In this paper, we decompose worldwide PISA mathematics and reading scores. While mathematics scores are still tilted towards boys, girls have a larger advantage in reading over boys. Girls' disadvantage in mathematics is increasing over the distribution of talents. Our decomposition shows that...