This thesis consists of three essays in the economics of education with an empirical focus on Mexico. The first two chapters study a college in Mexico whose admission decisions are made through a lottery. Some applicants are randomly assigned into a group that can immediately enroll and the rest into a group that can only do so after waiting one year. This "experiment" created a difference in the education trajectories of the two groups. I surveyed the applicants for the 2007/2008 academic year and found that, one and a half years after the first group enrolled, individuals in that group were 19 percentage points more likely to be enrolled than those that had to wait. In the first chapter, I explore the implications that this experiment has for the economic model of educational decisions. I show that the standard neoclassical model of educational decisions predicts minimal effect of deferral (i.e. having to wait) on educational attainment. However, I find evidence against this prediction since many of the applicants who had to wait one year did not come back to study. To account for these results, I extend the standard model by placing the education decision in a model of labor market search. This suggests the importance of variability in opportunity costs for explaining who enrolls in college at any given moment. I derive testable implications of the model and show that they are verified empirically. I also discuss alternative explanations of the impact of deferral and show they are inconsistent with observed patterns. I conclude that within-individual variation in opportunity costs is an important element in determining educational attainment. In the second chapter, I use this natural experiment to examine whether education increases patience. Since the lottery outcome had a significant impact on the probability of going to college, this experiment can be used to study the effects of education. The survey that I fielded measured the respondents' time preferences with a series of hypothetical inter-temporal choice questions. I find that individuals who were successful in the admission lottery were on average more patient, which points towards a causal effect of education on time preferences. The last chapter studies the impact of expenditures on the returns to schooling within a context of dramatic reductions in public spending. I match data on expenditures and pupil-teacher ratios from Mexico in the 1980's with individual earnings in 2007/2008 and find that the returns to education among individuals that went to poorly funded schools are lower than among those that went to better funded ones. I determine that within-state changes in educational expenditures and pupil-teacher ratios predict changes in the returns to education. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]