In this dissertation, I compile two papers. The first on assignments to public schools and the limits of school choice; the second on the impact of commodity price shocks on civilian collaboration and violence in civil wars. In chapter 1, I study the limits of school choice policies in the presence of residential sorting. Using data from the Boston Public Schools choice system, I show that white pre-kindergarteners are assigned to higher-achieving schools than minority students, and that cross-race school achievement gaps under choice are no lower than would be generated by a neighborhood assignment rule. To understand why choice-based assignments do not reduce gaps in school achievement, I use rich data on applicants' rank-order choices to estimate preferences over schools, and consider a series of counterfactual assignments. I find that an important part of the gap in achievement at the schools assigned to black and hispanic students relative to those assigned to white students is explained by travel costs to high-performing schools. Differences in preferences for schools explain a small part of the gap, while algorithm rules have no effect. Chapter 2 is joint work with Austin Wright. We propose a mechanism that rationalizes changes in violence in civil wars after economic shocks and test it with newly collected data. The rationale we propose relies on a theory of violence where political groups choose the type of violence -selective or indiscriminate- that maximize their expected control, and where information provided by civilian informants determine the relative effectiveness of these types of violence. Civilians, are producers of an agricultural good and choose the political group they will supply information to, if any, having considerations on expected revenue and chances of survival. We argue that increases in the price of commodities whose production relies on collaboration reduce the incentives of civilians to inform against fellow community members. Since information is necessary to effectively carry out selective attacks, a reduction in the information available to political groups will cause a reduction in selective violence. We use a text analysis algorithms to classify violent attacks and test the mechanism.