"Affirmative action policies are practiced around the world. This paper explores the welfare economics of such policies. A model is proposed where heterogeneous agents, distinguished by skill level and social identity, compete for positions in a hierarchy. The problem of designing an efficient...

"The SEED schools, which combine a "No Excuses'' charter model with a five-day-a-week boarding program, are America's only urban public boarding schools for the poor. We provide the first causal estimate of the impact of attending SEED schools on academic achievement, with the goal of...

"There are large and important differences between blacks and whites in nearly every facet of life - earnings, unemployment, incarceration, health, and so on. This chapter contains three themes. First, relative to the 20th century, the significance of discrimination as an explanation for racial...