A growing number of developing economies are providing cash transfers to poor people that require certain behaviors on their part, such as attending school or regularly visiting health care facilities. A simple ex ante methodology is proposed for evaluating such programs and used to assess the Bolsa Escola program in Brazil. The results suggest that about 60 percent of poor 10-to 15-year-olds not in school enroll in response to the program. The program reduces the incidence of poverty by only a little more than one percentage point, however, and the Gini coefficient falls just half a point. Results are better for measures more sensitive to the bottom of the distribution, but the effect is never large.