household interviews were conducted in French.

Panel C reports school characteristics. The average school in our sample is not small: it has 347 students and 10 teachers, half of whom hold a baccalaureate degree and half of whom participated in training in the ve years preceding the intervention. The schools are varied in their resources: 56 percent have electricity, and 23 percent have a library. Three-quarters of principals have a baccalaureate degree.

Treatment and control schools are very well balanced. All but two dierences (parental involvement in school and the percent of teachers who report receiving training in the past ve years, both for second grade) are insignicant at the 5% level. It is noteworthy that the precision of the dierence in test scores is very high, which bodes very well for our ability to detect even small eects of the program.<sup>8</sup> As explained above, some schools were inaccessible at baseline, and thus were only added to the survey in the rst follow up (although they participated in the randomization, and the treatment schools in this group were funded as planned). The exclusion from baseline was unrelated to treatment status, which explains why nevertheless baseline schools are balanced. In Appendix Table 6 we present descriptive statistics for all schools including those added at the rst follow up. As we expect, when we compare the characteristics of treatment and control schools which we did not expect to change as a result of the experiment there is no signicant dierence, other than possibly in distance from school. However this is just one signicant dierence among many dierences; jointly there are no dierences and this one is very small in magnitude. Hence, whether we look at schools surveyed at baseline or at the rst followup, there is no evidence of imbalances between treatment and control with respect to their time-invariant characteristics.

Another concern is that these 633 schools may be fundamentally dierent from other primary schools in Senegal as a result of the grant selection process (e.g., these schools were better organized to put together a good grant application). Thus, they may not constitute a random set of schools in Senegal and the results of this study may not generalize. In Appendix Table 7, we show characteristics of a nationally representative sample of Senegalese households using data collected

> 8With the exception of the index score, we chose not to standardize the mathematics, French, and oral scores. The tests were designed to appropriately measure the types of skills taught in the rst years of elementary school, and looking at the proportion of right answers in this test is a natural way to assess student knowledge in these subjects, and its progress over time. Furthermore, these scores are specic to Senegal, so standardization would not be useful for international comparisons. Even within sample, we show in Appendix B that the distribution of scores is highly non-normal, so a one standard deviation in test scores does not have the usual meaning. Nevertheless, for our main results we report standard deviations of control schools to convert results to standard deviations.

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