Cambodian provinces that constituted the original experiment population. These children were in grades 3 and 4 in 2008. Data collection for the baseline took place from December 2008 to January 2009, and data collection for the new round of follow-up surveys took place from December 2016 to May 2017. The subsample targeted those children that had not attrited in a previous round of tracking in 2011. The team was able to survey 3,294 respondents, or 86.1% of the target subsample. However, overall attrition rates were higher than in Pakistan and differential across experimental groups (e.g., 24.2% among grade-4 students in the control group and 32.7% among grade-4 students in the treatment group). Another shortcoming of the data collection in Cambodia is that we did not systematically collect the current location of respondents (this information is missing for 18% of the surveyed sample). The survey content was very similar to that of Pakistan. In particular, the team implemented both a cognitive and socioemotional skills assessment and collected data on labor market outcomes and family formation.

The cognitive assessment was a computer-adaptive math test in which respondents answered ten questions from a larger pool of 23 items. These items are aggregated in a cognitive skills index with a two-parameter Item Response Theory model.

To measure socioemotional skills, the team used the same Grit and “Big Five” self-reported scales as in Pakistan. We also measured growth mindset—the belief that one can get smarter through hard work and practice—using a 4-item scale. We also measured respondents’ locus of control—the degree to which people believe that they have power over the outcome of events in their lives, as opposed to external forces beyond their control—using a four-item scale. Finally, we administered the Strengths and Difficulties Questionnaire (SDQ), which is a brief behavioral screening questionnaire. All items are answered using a 5-point answer format that ranges from 1 (“Disagree strongly”) to 5 (“Agree strongly”). Cronbach’s alphas for these different measures, before and after acquiescence bias corrections, are displayed in Table 2. Only the SDQ passes the 0.7 threshold. The Cronbach’s alphas for the other measures range from 0.04 to 0.58. Moreover, we randomly resurveyed 13% of randomly selected respondents within the same week, using a subset of items. Thus, we can compute the test-retest correlations for the Big-Five constructs. These are low, with an average of 0.3 (Table 2), reflecting a large amount of measurement error. Moreover, when conducting exploratory factor analysis, the skills factor structure is not reproduced. Only three factors are retained, and one single factor encompasses many items that aim to measure different concepts.

# _D.3.2. Pakistan pilot_

Given the results from Laajaj and Macours (2021) and those from the data collection in Cambodia, we decided to conduct a large pilot before our data collection in Pakistan. We conducted the pilot in the district of Okara, between February and March 2018. Interested participants were invited to a central location, resulting in a total sample size of 403 pilot respondents. Then, two weeks after the completion of the first round, we tracked and re-surveyed a random half of them (201 respondents).

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