Among development agencies, conventional wisdom holds that educational expansion improves economic welfare and health, reduces inequalities, and encourages democratic political systems. We investigate the empirical foundations for these expectations in recent social science research. Consistent evidence indicates that health and demographic benefits result from educational expansion, and suggests that education enhances, but does not ensure, individuals’ economic security. However, the impact of educational expansion on growth remains debated, and decades of sociological studies offer evidence that educational expansion does not necessarily narrow social inequalities. Finally, considerable controversy surrounds the implications of educational expansion for democratization. Reasonable forecasts of the consequences of further educational expansions need to consider the diverse social contexts in which these expansions will occur.