In 1997, the federal government of Mexico introduced the Programa de Educación, Salud y Alimentación (the Education, Health, and Nutrition Program), known by its Spanish acronym, PROGRESA, as part of its renewed effort to break the intergenerational transmission of poverty. Beginning early 1998, IFPRI at the request of PROGRESA conducted an evaluation of its major rural anti-poverty program. For more information about IFPRI's work with PROGRESA, see Targeted Interventions to Reduce and Prevent Poverty . The experimental design used for the evaluation of PROGRESA takes advantage of the sequential expansion of the program in order to come up with a set of localities that serve the role of controls. Specifically, the sample consists of repeated observations (panel data) collected for 24,000 households from 506 localities in the seven states of Guerrero, Hidalgo, Michoacan, Puebla, Queretaro, San Luis Potosi and Veracruz. Of the 506 localities, 320 localities were assigned to the treatment group and 186 localities were assigned as controls. The 320 treatment localities were randomly selected using probabilities proportional to size from a universe of 4,546 localities that were covered by phase II of the program in the 7 states mentioned above. Using the same method, the 186 control localities were selected from a universe of 1,850 localities in these 7 states that were to be covered by PROGRESA in later phases. In November 1997 PROGRESA conducted a survey of the socio-economic conditions of rural Mexican households (Encuesta de Caracteristicas Socioeconomicas de los Hogares or ENCASEH) in the evaluation communities to determine which households would be eligible for benefits. Then based on PROGRESA's beneficiary selection methods, households were classified as eligible and non-eligible for participation in the program in both treatment and control communities. The first evaluation survey (Encuesta Evaluation de los Hogares or ENCEL) took place in March 1998 before the initiation of benefits distribution in May 1998. In combination these two surveys provide the baseline observations available for all households before the initiation of the distribution of cash benefits in the treatment villages. The rest of the evaluation surveys were conducted after beneficiary households started receiving benefits from PROGRESA. One round of surveys took place in October/November 1998 (ENCEL98O), which was well after most households received some benefits as part of their participation in the program. The next two waves took place in June 1999 (ENCEL98M) and November 1999 (ENCEL99N). A number of core questions about the demographic composition of households and their socio-economic status were applied in each round of the survey. These core questions were accompanied by specific questionnaires, focused on collecting information critical to a thorough evaluation of the impact of the program. The topics of these modules included collecting information about family background, assets brought to marriage, schooling indicators, health status and utilization, parental attitudes and aspirations towards children's schooling, consumption of food and non-food items, the allocation of time of household members in various activities, and self-employment activities. The preceding surveys were supplemented by school and clinic surveys, community questionnaires, data on student achievement test scores, and other school and clinic administrative data. The evaluation surveys (ENCEL) collected by PROGRESA did not allow for an evaluation of the nutritional component of the program. For the purposes of evaluating the nutritional component of PROGRESA separate surveys of the same families were carried out by the National Institute of Public Health (INSP) in Cuernavaca. These surveys included collection of data on anthropometric measures (weight and height) data of children, collection of blood samples for tests for anemia and other deficiencies.