When scale and replication work: Learning from summer youth employment experiments
中文摘要
本文将芝加哥和费城的两个新夏季青年就业实验与先前发表的证据相结合，以展示对一项干预措施在其规模扩大和情境变化时的重复研究如何指导公共投资决策。处理异质性的两个来源可能会破坏成功的人力资本干预措施的规模扩大与复制：处理本身的变化与个体反应程度的变化。结果表明，即使管理人员招募了额外的青年、雇佣了新的本地服务提供方、找到了更多的工作岗位并改变了项目内容，这些项目依然一致地产生了刑事司法介入的成比例大幅下降。利用城市内部的内生分层以及跨城市的62个新旧点估计的变异，揭示了个体反应程度的一个关键模式：影响随着每个人面临的社会代价高昂行为的风险呈线性增长。识别出更多能够结合这种对处理变异的稳健性以及对最边缘化群体产生更大效应的干预措施，有助于高效减少社会不平等。
Abstract
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 and changes contexts can guide decisions about public investment. Two sources of treatment heterogeneity can undermine the scale-up and replication of successful human capital interventions: variation in the treatment itself and in individual responsiveness. Results show that these programs generate consistently large proportional decreases in criminal justice involvement, even as administrators recruit additional youth, hire new local providers, find more job placements, and vary the content of their programs. Using both endogeneous stratification within cities and variation in 62 new and existing point estimates across cities uncovers a key pattern of individual responsiveness: impacts grow linearly with the risk of socially costly behavior each person faces. Identifying more interventions that combine this pattern of robustness to treatment variation with bigger effects for the most disconnected could aid efforts to reduce social inequality efficiently.