Cash transfers can help poor families to meet the costs associated with sending their children to school. Demand constraints are a major impediment to schooling attainment in rural areas. Educational grants can contribute to raise schooling attainment in rural areas and thereby to close the gap between educational levels in rural areas and national levels. In 1997, the Mexican government initiated such a program of cash transfers, called PROGRESA, targeted to children living in poor and extremely poor rural regions. The present work shows that the program effectively retains children in school leading to important gains in schooling attainment. The grants succeed at lowering the drop out rates by 30-45\% for the eligible grades of primary a...