The anti-poverty program in Mexico, PROGRESA, provides monetary transfers to families that are contingent upon their children's regular attendance at school. The benefit levels are intended to offset the opportunity costs of not sending children to school and vary with the grade level and gender of the child. The initial phase of the program was implemented as a randomized social experiment. This paper uses a Markov schooling transition model applied to the experimental data to assess the impact of the educational subsidy program along several dimensions, including effects on initial ages of school entry, dropout rates, grade repetition rates, and school reentry rates. The findings show that the program effectively reduces drop-out rates and facilitates progression through the grades, particularly during the transition from primary to secondary school.