Preschool Quality and Child Development
研究评估了哥伦比亚两项提升公立学前教育质量的干预措施：政府主导的全国性增加经费（主要用于雇佣助教）未改善儿童发展，而额外增加教师培训则显著提升了儿童认知发展，尤其对弱势背景儿童效果更明显。
Globally, access to preschool has increased dramatically but its quality is often poor. We evaluate two interventions aimed at improving the quality of public preschools in Colombia. The first, designed by the government and rolled-out nationwide, provided preschools with significant extra funding, mainly earmarked for hiring teaching assistants (TAs). The second, for a small additional cost, also offered training for existing teachers. We show that the first intervention did not improve child development, while the second led to significant improvements in children’s cognitive development, especially for those from more disadvantaged backgrounds. We argue these dramatic differences can be explained by the two interventions having different impacts on teachers’ behavior. The first led teachers to reduce the time they spent in the classroom, including on learning activities. The addition of the training offset this adverse effect of TA provision on teachers’ learning activities and improved the quality of teaching.