have usually either repeated a grade or entered school later than others. The ethnic composition controls have some predictive power. Program impact estimates are similar if these explanatory variables are excluded, although estimates are less precise.<sup>13</sup> Estimates are largely unchanged when individual demographic controls collected in the 2002 student questionnaire – including parent education and household asset ownership – are included as explanatory variables,<sup>14</sup> and interactions of the program indicator with these household socioeconomic proxies are not statistically significant at traditional confidence levels (regressions not shown), suggesting that better-off residents do not gain disproportionately.

Test score effects in Teso district are near zero and statistically insignificant (Table 5, Panel B, regression 2). This is consistent with the hypothesis that winning a scholarship was less desirable in Teso due to mistrust of the NGO or lack of social prestige associated with winning the award, and also with the hypothesized bias due to sample attrition in Teso. It remains unclear whether there might have been larger program effects had there been no lightning tragedy in 2001, or how common the problems of program implementation and sample attrition encountered in Teso would be in other settings.<sup>15</sup> The scholarship program not only significantly raised test scores when it was first introduced in 2001, but also continued to increase scores of cohort 1 girls in program schools during 2002: the point estimate in year two is 0.24 (standard error 0.08, Table 5, Panel C regression 1) for the restricted sample, 13 For instance, the program impact for Busia cohort 1 girls is still exactly 0.27 standard deviations in this case, but the standard error rises to 0.19, while the program impact for cohort 2 rises to 0.31 with standard error 0.18 (significantly different than zero at 90 percent confidence) – regressions not shown. Standard errors fall considerably when disturbance terms are not clustered at the school level; for instance, the standard error on the overall effect for girls and boys in Busia and Teso (as in Table 5, Panel A) decreases from 0.05 to 0.02.

14 These are not included in the main specifications because they were only collected for a subsample of students, those present on the day of 2002 survey administration, and would thus reduce sample size.

15 To disentangle the effect of being in a Teso district school from the effect of the lightning strike (in a specification that pools the Busia and Teso data for all girls and boys), we included an indicator variable for Teso district, and an interaction of the Teso indicator with the program indicator, as well as an indicator for schools located with 6 km of the lightning strike, and the interaction of this distance term with the program indicator. The coefficient estimate on the lightning distance and program interaction term is large and negative but not statistically significant (-0.10, standard error 0.13), while the coefficient estimate on the Teso-program interaction term remains negative and marginally significant (-0.21, standard error 0.11) – suggesting that the lightning strike alone cannot account for the negative Teso effect. Thirteen schools, or approximately 10 percent of the sample, were located within 6 km of the strike. Interaction results are similar for distances between 5-7 km from the lightning strike.

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