This study exploits the setting provided by the PROGRESA/OPORTUNIDADES intervention to estimate a child care production function and understand the mechanisms through which conditional cash transfer programs can affect child outcomes. More specifically, it aims to investigate whether the program generates changes in the provision of child care across household members that result in increased (maternal) care and ultimately in improved child cognitive and socio-emotional development. It also intends to identify program impacts along other dimensions such as maternal education and age or child birth order