Evaluators of education interventions are increasingly designing studies to detect impacts much smaller than the 0.20 standard deviations that Cohen (1988) characterized as "small." While the need to detect smaller impacts is based on compelling arguments that such impacts are substantively meaningful, the drive to detect smaller impacts…

Psacharopoulos has found a declining rate-of-return to education pattern across levels of per capita income, using international data. A reexamination of Psacharopoulos's cross-country data refutes his declining rate-of-return hypothesis and points to diversity of cross-country experience as a possibly significant factor in interpreting the data.…