When scale and replication work: Learning from summer youth employment experiments

This paper combines two new summer youth employment experiments in Chicago and Philadelphia with previously published evidence to show how repeated study of an intervention as it scales changes contexts can guide decisions about public investment. Two sources treatment heterogeneity undermine the scale-up replication successful human capital interventions: variation itself individual responsiveness. Results that these programs generate consistently large proportional decreases criminal justice involvement, even administrators recruit additional youth, hire local providers, find more job placements, vary content their programs. Using both endogeneous stratification within cities 62 existing point estimates across uncovers a key pattern responsiveness: impacts grow linearly risk socially costly behavior each person faces. Identifying interventions combine this robustness bigger effects for most disconnected could aid efforts reduce social inequality efficiently.