of exposure. The average effect of three years of exposure on the probability of enrolling in seventh grade is very large and precisely estimated ( _p_ -value _<_ 0.001). The magnitude of this effect implies that the enrollment rates in these disadvantaged and rural areas achieve the secondary school enrollment rates in urban Mexico (95 percent). The average marginal effect of an extra year of the program is +10 percentage points ( _p_ -value = 0.006) in the probability of enrolling in seventh grade. The effect of two years of exposure, although not statistically different, is larger than the experimental estimate displayed in Table 2 (fifth column) suggesting that the impact does not fade out after one year.

# **6.2 The Effect of the Program Beyond the Evaluation Sample**

We now broaden our analysis to the entire population of schools in the state of Chiapas. We examine whether the _Plus_ modality of the program at scale has promoted educational opportunities for children in these disadvantaged communities, possibly resembling the results from the second field experiment (see Section 3). To do so, we match administrative records on the government rollout of the program during the fall of 2017 with village-level educational outcomes from the population census data (data collection in the fall of 2019) for the majority of the schools and communities, which include those that were part of the second experiment.<sup>20</sup> Our first outcome is the village-level lower-secondary enrollment rates among children between 12 and 14 years old. This variable is available in the census for 1,417 communities in Chiapas. It is not immediately comparable with our previous measure of enrollment in seventh grade for two reasons. First, the census-based information represents the stock (rates) of children enrolled in secondary school in a given year, while our previous measure represents the flow of new students enrolling in secondary schools. Second, the census-based variable includes children in the village who are enrolled in primary schools that are not eligible for the API program, which converts the analysis of the program at scale into an intent-to-treat analysis. Another educational outcome from the population census that we use is the rate of child literacy for children between eight and fourteen years old, which represents an available measure of children’s achievement. This variable is available

> 20The match between the universe of schools and the localities of the population Census is one to one, as each village has at most only one primary school. The coverage of the census data is not universal, and we were not able to match nearly one-third of the 2,063 schools in Chiapas in 2019. For both educational outcomes in the census data we cannot reject the hypothesis that the probability of missing observations is balanced with respect to the program assignment ( _p_ -values for secondary school enrollment and child literacy are 0.728 and 0.430, respectively). For further details on the census sampling design, please refer to: `https://www.inegi.org.mx/contenidos/productos/prod_serv/contenidos/espanol/bvinegi/ productos/nueva_estruc/702825197629.pdf` , accessed on August, 2022.

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