In this dissertation, I address the issue of social inequalities in education and the role of the education system in confronting them. The project involves two main parts, one empirical and the other conceptual. In the first part--chapters 1 and 2--I address the practical dimension of how to reduce social inequalities in education by exploring two illustrative examples from Chile. First, I examine the effects of a school finance reform implemented in Chile in 2008. This reform changed the school funding formula from one based on student enrollment to one that gives between 50 to 60 percent more funding to each student from a lower socioeconomic background. This study presents evidence on the effects of this reform on student academic achievement in math and language. The evidence relies on the use of comparative interrupted time series analysis to identify the impact of this policy. The analysis uses the changes in student test scores from before to after the implementation of the policy between participating, non-participating, and late entry schools. The results indicate statistically significant differences in math performance gains of 4th graders (0.18 SD) after 4 years of treatment compared to students without treatment, and 0.07 SD in language gains. Second, I explore the potential impact of redistributing teacher quality to reduce educational inequalities related to social background. This study takes advantage of a unique data collection effort developed to examine the extent to which differences in student achievement in middle school (8th grade) and high school (10th grade) in math are related to differences in classroom practices as well as to content and pedagogical knowledge of their teachers. Using a value-added approach, this study provides evidence that measures of teacher characteristics are predictive of student achievement gains in middle and high school mathematics. In middle schools, the results indicate that students with teachers 1 SD above the average in terms of teaching practices and pedagogical knowledge, and also certified in their content knowledge, perform 0.07 SD above the average. Similarly, high school students in similar circumstances perform 0.09 SD higher than the average. Thus, the results of this study provide promising clues for the improvement of both quality and equality of student learning. Providing feedback and improving teacher quality on the studied dimensions could support a more equitable distribution of student achievement by SES. In the second part--Chapter 3--I address the question of the role of the education system in addressing and mitigating educational inequalities. Specifically, I develop a conceptual framework to help answer the question of how much mitigation from the government is enough. I argue that--in addition to ethical considerations--social preferences, socio-political and economical configuration, as well as technical limitations of the education system should also be considered in defining the role of society and the education system in counteracting education inequalities. The framework articulates how those components are related to one another and how understanding them helps determine the most appropriate response to the problem of mitigation. Specifically, the framework addresses the question of how much counteraction is enough by decomposing it into four overarching questions: 1) what are the most fundamental and valued goals in society? 2) What are considered legitimate sources of advantage--inside and outside education--to achieve those socially valued goals? 3) What is the appropriate role of education in determining chances of achieving those goals? 4) What is the appropriate role of education in mitigating unfair advantage? The answers to these questions yield a standard of mitigation: education inequalities should be counteracted to the extent they no longer constitute a source of unfair advantage in the achievement of valuable goals. In. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]