Quotas reduce the disparity between public and private education.

Unicamp and USP recently announced the adoption of a quota system in their entrance exams for students from public schools, Black, mixed-race, and Indigenous students.

Every year, 18 million students participate in the Brazilian Mathematics Olympiad for Public Schools (OBMEP). Of these, six thousand (3.3 out of every ten thousand) are awarded a silver or bronze medal and 500 (2.8 out of every one hundred thousand) receive a gold medal.

We calculated the average ENEM (Brazilian National High School Exam) scores of all public school students who won gold medals in the OBMEP (Brazilian Mathematical Olympiad for Public Schools) from 2009 to 2015. In Mathematics, the average was 827; in Natural Sciences 638; in Human Sciences 673; in Language 611; and in Writing 704. The result in Mathematics means that these students are among the top 0.054% in the subject (the fifth best score out of ten thousand).

Despite their remarkable performance in Mathematics, these results would not qualify them for admission to a good Engineering course through the general admission system, a field sought by more than half of the OBMEP award winners. At UFRJ, for example, the cutoff scores in 2016 were 771 for Basic Cycle Engineering, 787 for Civil Engineering, and 784 for Computer and Information Engineering. At UFRJ, the top math performers would have an average score of 702.

The math results in the ENEM exam from OBMEP medalists reveal potential far above average for the exact sciences. However, a university entrance selection system should be based not on candidates' past performance, but on an assessment of their future performance. Which soccer player should be hired to take penalty kicks? An 18-year-old athlete, trained by the best teams in the country, who scores 70% of his penalties, or another who converts 65% having only played for amateur teams?

The quota system mitigates the disparity between public and private education and has been successful. From 2009 to 2012, UFMG (Federal University of Minas Gerais) granted a 10% bonus on entrance exam scores to students from public schools; 15% if they declared themselves Black, mixed-race, or Indigenous. In 2013, it replaced this program with quotas for these categories, increasing the reserved places annually, up to 50% in 2016.

A 2016 report from UFMG (Federal University of Minas Gerais) on the impact of affirmative action indicates that the academic performance of those benefiting from the bonus and quota students admitted from 2009 to 2013 was equal to or higher than that of students who entered through open competition; dropout rates were lower than or equal to that of students admitted through open competition. In 2014, with 25% of places reserved for quota students, the relationship reversed among those with a per capita family income of less than 1.5 minimum wages, and remained identical among the others.

More detailed analyses are needed to measure the effect of this public policy. Some studies indicate that the bonus did not alter the proportion of Black students in universities. There is also no evidence to affirm or deny that it exclusively benefited students from good public schools, such as the Colégios de Aplicação (application schools), military schools, or Federal Institutes.

In any case, the examples from OBMEP and the UFMG report show that the quota system is justified exclusively from the point of view of merit. It has enabled entry into university for students from public schools with lower ENEM scores, but whose academic performance has been equal to or higher than that of those admitted through open competition.