Preschool quality and child development

Globally, preschool enrollment has surged, but its quality is often poor. We evaluate strategies to improve quality of public preschools in Colombia. The first, designed by the government and rolled out nationwide, provided extra funding, mainly earmarked for hiring teaching assistants. The second also offered low-cost training for existing teachers. The first intervention had no effect on child development, while the second improved children’s cognitive development, especially for more disadvantaged children. This pattern can be explained by the interventions affecting teachers' behavior differently. The first led teachers to reduce their classroom time, including learning activities, while additional training offset the adverse effect on learning activities and improved teaching quality.