"Per capita income in the richest countries of the world exceeds that in the poorest countries by more than a factor of 50. What explains these enormous differences? This paper returns to several old ideas in development economics and proposes that linkages, complementarity, and superstar...

Within-country differences in educational outcomes are compared for a large group of industrialised countries. We investigate where inequality is greatest, the association between inequality in learning and average levels of learning, the interpretation of measured levels of inequality, and...