the ENLACE. Furthermore, in conversations with INEE, the suggested proportion of students copying was reported to be in nearly all cases less than 10%. Thus, we consider unlikely that the presence of some cheating/copying biases our results on the ENLACE scores.

For our main analysis, we begin with the database of all sixth graders taking the ENLACE test in the school year 2007-2008, the second year in which ENLACE was applied. We focus on this group because it is the group for which we can merge the largest number of follow-up tests. In particular, we can merge to this database of sixth graders in 2007-2008, test results in 2008-2009 (seventh grade for most), 2010-2011 (ninth grade for most) and 2013-2014 (twelfth grade for most). In this way we construct a panel of achievement tests over a period of six years. Because program effects on enrollment and attendance in the primary level are lower than in subsequent levels (Behrman, Sengupta and Todd, 2005), we treat the 2007-2008 sixth grade scores as a baseline, that is unlikely to have been significantly impacted by PROSPERA although households in which the children in our database reside, may have been receiving grants before this period. To the extent achievement of PROSPERA children had already been affected in our data before the school year 2007-2008, the results we report here represent an underestimate of total program effects on achievement.<sup>5</sup> This approach also allows us to treat taking the ENLACE test as a proxy for being enrolled in school. Although defining enrollment in this way underestimates the overall level of children enrolled in school, estimates of the impact of PROSPERA on enrollment will be unbiased assuming the implementation of the ENLACE does not differentially affect who attends school the day of the application with regard to PROSPERA receipt. This seems a reasonable assumption.

The construction of the panel allows us to study educational trajectories of youth between sixth grade and twelfth grade beginning with sixth graders in 2007-2008. We choose this panel as it allows following students for the longest time period possible with the ENLACE. We merge ENLACE exams from seventh grade (first grade of secondary school) in 2009-2010, ninth graders in 2011-2012 and twelfth graders in 2014-2015. Ideally, we would have had ENLACE scores for tenth graders in 2012-2013 so as to better analyze the transition from secondary to high school, but ENLACE tests were only administered in high schools to twelfth graders.

The ENLACE data also contain information on the type of school attended. Thus, we are also able to study program effects on enrollment in different types of schools in addition to achievement test results. There are a number of pathways youth may take, for instance, sixth graders may dropout or repeat sixth grade, or they may enter a tele-secondary, technical, general or private school. At the secondary level we study enrollment in technical, tele-secondary or general schools (less than 1 percent enroll in private secondary schools). At the high school level, we distinguish between general high schools, technical high schools, CONALEP high schools and private high schools.

> 5 Data available for this version of the paper did not include students who continued to be enrolled but repeated a grade. Thus, these students are excluded in this analysis. Failure rates are, however, relatively low in sixth grade and beyond (Behrman, Sengupta and Todd, 2005).

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