As large urban school districts increasingly turn to market-based reforms, arguing that they will improve school quality, better meet diverse student and family needs, and level the playing field for disadvantaged families, the distributional effects of those policies are still poorly understood. A growing literature on the bounded and embedded nature of families' school choices has raised equity concerns about who has access to schools of choice, how they make their choices, and how resulting enrollment patterns may be further segregating students by race and socioeconomic status, above and beyond the impact of housing segregation. This dissertation uses a mixed methods approach to fulfill two goals. First, an institutional analysis will provide a robust characterization of the complex policy, market, and sociological factors that structure families', school leaders', and district administrators' school choice decisions. Second, a quasi-experimental design exploits the gradual expansion of public elementary schools of choice in New York City from 2010-11 to 2014-15 to estimate the distributional effects on nearby zoned elementary schools. Geospatial analysis is used to identify treated schools, propensity score matching is used to identify a comparison sample of zoned schools, and a comparative interrupted time series models the difference in trends for multiple school-level outcomes between the treatment and comparison sets. Findings reveal that zoned schools treated by a nearby school of choice see a decrease in the proportion of English Language Learners, an increase in racial/ethnic diversity, and an increase in the share of chronically absent students. These results, however, are small and moderated by the baseline level of segregation and whether the school was treated by a charter or non-zoned traditional public school. This adds new evidence about the systemic effects of choice, with important policy implications for ways to support affected zoned schools, strategically locate new schools of choice, and further reduce barriers to choice to ensure equitable access. [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.]