# **4. Data**

The data we use in this analysis come from three sources. First, we use the SOFES database containing detailed information on all students receiving a credit from SOFES. Second, we use data from a large-scale survey (carried out in 2003) among students and graduates at Mexican private universities who are members of SOFES. Finally, we use data from a household survey on educational attainment and incomes. In this section we describe the data sources. As the Mexican household survey is well-documented, we concentrate on the first two sources.<sup>6</sup>

# _4.1 SOFES database_

The database includes information on the student’s educational attainment (for instance grade point averages at various school levels), socio-economic background (e.g. family income, educational attainment of the father, employment information), study program and grade point average during the last term of the program, and a lot of other information. The important variables of the SOFES database are summarized in Appendix Table 1.<sup>7</sup> The first column refers to Bachelor-students with a SOFES-credit, and the second column refers to Masterstudents with a SOFES-credit. With regard to educational attainment, the SOFES database provides information on the three previously attended schools. In case of a Bachelor-student, this means upper secondary school ( _Bachillerato_ ), lower secondary school ( _Secundaria_ ), and primary school ( _Basica_ ). In case of a Master-student, the last three attended programs are the Bachelor-program, high school, and lower secondary school. This distinction should be kept in mind when interpreting the results. The table shows that Master-students have slightly higher grade point averages at upper secondary school and lower secondary school than Bachelorstudents. In about half of the cases it is reported that the student attended a private school. As most students in primary and secondary education attend public schools, this suggests that attendance of private schools increases the likelihood of attending university (and this is confirmed in the econometric analysis on Mexican census data presented in Section 5). About half of the SOFES-recipients in Bachelor-programs are female, and 41% of the SOFES-students at the Master-level are female. The average educational attainment of the father is high school.

> 6 See, for instance, the documentation provided at <u>http://cursos.itam.mx/rodrigo/encuestas/enigh/2000/.</u> 7 As the information is double-checked by SOFES, the data quality in the SOFES database is high. There are however a few peculiarities and we cleaned the data in the following way. We dropped missing cases on study field, students in a Ph.D.-program, extreme observations on grade point averages (lower than 6 and larger than 10), extreme reported income levels (lower than 1,000 pesos per month and larger than 50,000 pesos per month), very low reported credit levels (lower than 0.2), very low reported levels of the socio-economic stratification index (lower than 2.1), and very high reported levels of additional financial support (more than 30,000 pesos). Finally, we only include people who are studying at the moment of data collection (June, 2003). The data used in this paper is a random sample of the total SOFES database.

7