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. (JEL I24, I28, J13, J24, O15)

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.