in the RD-approach is smaller than the survey estimations imply, hence (self-)selection could create a bias in the survey results. In terms of impact on repetition, the study does not find a statistically significant impact.

- (iii) <u>Impact on part time job: Exploring both the SOFES survey (external margin) and the SOFES database</u> (internal margin), we find that SOFES recipients work more often than students without a loan.  The survey data suggest that the likelihood of working on the side increases by 8 percent, while the SOFES database suggests that part-time employment increases by around 30 percentage-points for master students. This is consistent with the hypothesis that students in the SOFES program are still credit constrained, and therefore have to generate income while studying.

<u>(iv) Impact on career choice:</u> There seems to be no clear direction of impact. The two estimation methods and data sources suggest different impacts and are not systematically statistically significant. The RD approach for master students using the SOFES database marginally corroborates the pattern found analyzing the survey data: an impact of student loans shifting away from Economics and Administration toward Humanities and Social Sciences (and perhaps also to Engineering and Natural Sciences). However, some of the RD-estimations for bachelor students contradict this pattern.

For the survey data, it should be noted that the treatment group of SOFES beneficiaries differs from the control group on a series of important characteristics. In accordance with the organization’s objectives: (i) The SOFES recipients tend to come from less favorable backgrounds than non-SOFES students: family income of non-SOFES students exceeds that of SOFES students by 48%, the parents’ education level is higher for nonSOFES students than for SOFES-beneficiaries, and 51% of SOFES beneficiaries attended public upper secondary education compared with 37% for non-SOFES beneficiaries; and (ii) despite the above differences, the SOFES beneficiaries tend to be slightly more talented in terms of grade point average. These factors point to differences between the two groups. This suggests an impact of SOFES in terms of increased accessibility of higher education, which is consistent with the above findings on the importance of financial aid for accessibility. The difference could also imply that the two groups are different in other un-observable characteristics and the survey estimates may therefore be subject to biases.

The findings for the SOFES program in this paper raise several **_policy questions regarding accessibility of higher education in Mexico_** .

The findings suggest that SOFES is successful in relieving credit market problems and promoting human capital formation at a very marginal or no cost to the public coffers. Tuition fees charged at high-quality private universities are large, and often take up half or more of family income. Further, there are additional costs such as books and living costs. Consequently, also relatively affluent families face difficulties in financing these costs without a student loan program. This is consistent with other studies, such as Dynaski (2003), that have found that relatively affluent families in the United States have a strong response to financial aid than lowincome families.

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