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.
We examine the channels through which a randomized early childhood intervention in Colombia led to significant gains in cognitive and socio-emotional skills among a sample of disadvantaged children aged 12 to 24 months at baseline. We estimate the determinants of parents' material and time investments in these children and evaluate the impact of the treatment on such investments. We then estimate the production functions for cognitive and socio-emotional skills. The effects of the program can be explained by increases in parental investments, emphasizing the importance of parenting interventions at an early age.