We study whether extending the school day in public schools—an implicit subsidy on
childcare—affects women's fertility decisions in Mexico. Exploiting the staggered implementation
of a nationwide policy directed to children 3 to 12 years of age and information
on the universe of births, we find that full-time schools availability reduces fertility by 7.8%
over the course of 8 years, and that this effect is fully explained by reductions in fertility
among second and higher-order births. Fertility decreases more for less educated women
in municipalities with stronger labor markets and those living in poorer municipalities.