This paper empirically evaluates the effects of college admissions policies on high school student performance. To this end, I build a model where high school students decide their level of effort and whether to take the college admissions test, taking into consideration how those decisions may affect their future university admission chances. Using Chilean data for the 2009 college admissions process, I structurally estimate the parameters of the model in order to study the implications of two types of counterfactual experiments: (a) a SES-Quota system, which imposes the population’s SES distribution for each university; (b) increasing the high school GPA weight. The results from these exercises support the claim that increasing the level of equal college opportunities may boost the amount of effort exerted by high school students. Specifically, I find that: (1) average effort significantly increases as opportunities are equalized across different socioeconomic groups. (2) There is a moderate improvement in high school student performance, which is relatively important for certain groups. (3) The highest reactions in terms of exerted effort come from those students who also change their decision about taking the college admissions test. (4) Neither of these policies increases the percentage of students taking the national test for college admission, which is consistent with the fact that in this policy implementation there are winners and losers. However, there are relevant variations in who is taking such a test; in particular, this percentage increases for low-income students and those who have higher level of learning skills. (5) Because the SES-Quota system uses the existing information more efficiently, it implies a more efficient student allocation to equalize opportunities.