private schools in Pakistan, the 112 villages in these districts were chosen randomly from the list of all villages with an existing private school. As would be expected given the presence of a private school, the sample villages are generally larger, wealthier, and more educated than the average rural village. Nevertheless, at the time of the survey, more than 50 percent of the province’s population resided in such villages (Andrabi, Das and Khwaja, 2006).

The survey covers all schools within the sample village boundaries _and_ within a short walk of any village household. Including schools that opened and closed over the three rounds, 858 schools were surveyed, while three refused to cooperate. Sample schools account for over 90 percent of enrollment in the sample villages.

The first panel of children consists of 13,735 third-graders, 12,110 of which were tested in Urdu, English, and mathematics. These children were subsequently followed for two years and retested in each period. Every effort was made to track children across rounds, even when they were not promoted. In total, 12 percent and 13 percent of children dropped out or were lost between rounds one and two, and two and three, respectively.<sup>10</sup> In addition to being tested, 6,379 children—up to ten in each school—were randomly administered a survey including anthropometrics (height and weight) and detailed family characteristics such parental education and wealth, as measured by principal components analysis analysis of 20 assets. When exploring the economic interpretation of persistence, we also use a small subsample of approximately 650 children that can be matched to a detailed household survey that includes, among other things, child and parental time use and educational spending.

For our analysis, we use two subsamples of the data: all children who were tested in all three years (N=8120) and children who were tested _and_ given a detailed child survey in all three years (N=4031). Table 2 presents the characteristics of these children split by whether they attend public or private schools. The patterns across each subsample is relatively stable. Children attending privates schools are slightly younger, have fewer elder siblings, and come from wealthier and more educated households. Years of schooling, which largely captures grade retention, is lower in private schools. Children in private schools are also less likely to have a father living at home, perhaps due to a migration or remittance effect on private school attendance.

The measures of achievement are based on exams in English, Urdu (the vernacular), and mathematics. The tests were relatively long (over 40 questions per subject) and were designed to maximize the precision over a range of abilities in each grade. While a fraction of questions

> 10Attrition in private schools is 2 percentage points higher than in public schools. Children who drop out between rounds one and two have scores roughly 0.2 s.d. lower than children that don’t. Controlling for school type and drop out status, drop outs in private schools are slightly better (0.05 sd) than children in public schools, although the difference is only statistically significant for math. Given the small relative differences in attrition between public and private schools, additional corrections for attrition are unlikely to significantly our results.

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