This thesis is composed of three empirical essays that share the theme of education policy evaluation. Chapter 1 looks at cognitive spillovers between siblings who live in the same household. The research question asked is whether such spillovers exist, and what their magnitude may be. Using longitudinal data on children aged 5 to 14 and living in the United States, I identify positive, significant and sizable cognitive spillovers between siblings. In the light of these findings, education policies that increase the cognitive achievement of any target population of children may also indirectly benefit their cohabiting siblings. Chapter 2 evaluates the outcome of a decentralization reform that has affected public education in Colombia. Municipalities with more than 100 thousand inhabitants were made autonomous in the management of public education on their territories, while cities below that threshold were not given autonomy. I exploit this quasi-experimental setup to evaluate the impact of local autonomy on educational quality. I find that autonomy was beneficial for municipalities that were highly developed at the time of the reform, but the impact was negative for low-developed ones, increasing inequality across regions. These results sound a note of caution about the potential consequences of decentralization reforms, in educational contexts similar to the Colombian one. Chapter 3 is coauthored with Fabio Sánchez Torres at the University of Los Andes, and looks at how quality assurance mechanisms in the careers of public school teachers have affected student performance in Colombia. The main novelties consist in a selective entry examination, a probation period and permanent evaluation processes. We find that teachers who operate under the new regulation noticeably improve pupils’ achievement with respect to colleagues who follow the old rules, which feature very few incentives for teaching quality. Our findings may provide education policy guidance to several Latin American countries, in which current teacher regulations resemble the former Colombian one.