Universal preschool enrollment was implemented in Mexico through a phased in scheme from 2004 to 2008. A subsequent increase in preschool enrollment was observed. Through a difference-in-difference analysis, I exploit the state-year variation in preschool enrollment to measure the effect of universal preschool enrollment on mother’s employment. I compare labor outcomes of mothers of preschool-age children to mothers of younger children, mothers of older children and non-mothers. Data come from the Mexican Income and Expenditure Household Survey (1996 to 2012) and the Mexican Ministry of Education.

Results indicate that universal preschool enrollment increased the employment of mothers of 3-, and 4-year-old children in 24 to 55 percentage point (pp), respectively, compared to mothers of younger children. When compared to mothers of older children, universal preschool increased mothers’ employment by 9-28 pp and when compared to non-mothers the increased ranged from 29 to 40 pp. In adjusted models where the treatment is subject to a child’s actual enrollment (and age of the child varies), the effects increase for mothers of 3-year olds across all comparison groups. For mothers of 4-year olds the effects decrease by a third, when compared to mothers of younger and older children, but increase when compared to non-mothers.