DOI: 10.25549/usctheses-c40-362744
title: Residential segregation of ethnic minorities  and its relationship to travel behavior and access to opportunities

description: My dissertation comprises three essays investigating how residence in segregated ethnic neighborhoods shapes the travel behavior of ethnic minorities and their physical access to opportunities. Racial residential segregation has been a long-standing and ongoing issue in the U.S. Therefore, understanding the impacts of ethnic neighborhood residency on the lives of ethnic minorities has become increasingly critical. However, as most previous studies focused on labor market outcomes, the effects of residence in segregated ethnic neighborhoods on travel behavior or accessibility have been rarely investigated despite its importance in addressing social justice and infrastructure development issues. Furthermore, although there may be considerable heterogeneity across ethnic neighborhood types and ethnic minority groups, past studies on the subject have not discussed the differences across these types and groups. I conduct in-depth investigations from a transportation perspective of what it means for ethnic minorities to live in segregated ethnic neighborhoods and how this meaning can vary based on racial/ethnic group. ❧ The first essay focuses on immigrants, and investigates whether and why residence in ethnic neighborhoods affects immigrant travel behavior. While previous studies have found distinctive travel behaviors among immigrants residing in ethnic neighborhoods, such as higher rates of carpooling and transit use, it has remained unclear what characteristics of ethnic neighborhoods motivate such travel behavior. Not only do ethnic neighborhoods, on average, have more compact and dense built environments, but they also have unique social environments based on ethnic networks. Using the 2012-2013 California Household Travel Survey, this study contributes to the literature by decoupling the social network effects on immigrant travel behavior from the effects of the built environment in those neighborhoods. The results demonstrate that ethnic neighborhoods play a critical role in the formation of effective ethnic-based social networks that increase the use of inter-household carpools. However, the higher use of public transit among immigrants living in ethnic neighborhoods seems to be a result of a transit-rich environment in such neighborhoods rather than of any social network effects within neighborhood residents, as posited in previous studies. ❧ The second essay is an extension of the first, but it focuses on comparing the relationship between residence in co-ethnic neighborhoods and the travel behavior of ethnic minorities across race/ethnicity and immigration status. Previous studies in sociology and economics have identified two types of ethnic neighborhoods: those that are formed non-voluntarily due in large part to racial discrimination in the housing market, such as African American neighborhoods, and those that are choice-based and self-segregated, such as Asian and Hispanic neighborhoods. As the factors that influence the formation of these neighborhoods differ significantly, the travel outcomes of the neighborhood residents, specifically inter-household carpooling, is expected to vary across ethnic neighborhood types. For present purposes, inter-household carpooling is employed as a proxy for local social networks. Using the 2009 National Household Travel Survey, I estimate the travel mode choices of ethnic minorities and find that co-neighborhood residency increases the probability that both Hispanics and Asians will form inter-household carpools for non-work purposes regardless of their immigrant status. This supports previous findings related to ethnic networks in such neighborhoods. In contrast, and as expected, the effects of black neighborhood residency on the formation of inter-household carpools are insignificant for African Americans. These findings therefore suggest that the constraints related to residential location choice, which vary by racial/ethnic group, may result in differences in local social networks observed via carpools across ethnic neighborhood types. ❧ While the first two essays investigate actual travel behavior among ethnic minorities, the final essay examines physical access to various types of opportunities in segregated ethnic neighborhoods that potentially affect both residents’ travel behavior and relevant socio-economic outcomes. Opportunities that I investigate include both jobs and non-work-related opportunities, such as schools and healthcare facilities. Previous studies have focused on job accessibility, but research on access to non-work-related opportunities is still in its infancy. I classify the neighborhoods within the urbanized Los Angeles region into 10 types based on their racial/ethnic characteristics and median household income. The results show that ethnic neighborhoods are heterogeneous in terms of their access to opportunities. Specifically, I find that on average, low-income ethnic neighborhoods in the Los Angeles region have higher access to opportunities by both car and transit than do wealthy white neighborhoods. However, middle-to-high-income, racially mixed and Hispanic neighborhoods have less access to most opportunities located within a 30-minute travel period via transit than other neighborhoods. The findings also demonstrate that modal disparity (car versus public transportation) is far more severe than spatial disparity with regard to access to opportunities, as drivers seem to have between 12 and 150 times greater accessibility to opportunities within 30 minutes than transit users do, depending on opportunity type. Considering that the higher percentages of ethnic minorities do not have vehicles in their households, they likely experience serious mobility issues even if they tend to live in neighborhoods with better access to opportunities than other neighborhoods.