Prof. Alice Xu: Segregation, Spatial Externalities, and the Privatization of Urban Services

Why do cities of comparable size and fiscal capacity provide different levels of public goods? I argue that politically polarized cities under-provide public goods. In particular, the geographic configuration of cities –their degree of class-based segregation– determines patterns of polarization and of cross-class political coalitions that form to address the spatial externalities between groups. Segregated cities have reduced spatial externalities (e.g., sewage run-off, waterborne diseases, organized crime) that spill over from impoverished “slum” settlements to the middle class. Conversely, in integrated (de-segregated) cities, the scale of such externalities undermines the efficacy of private services (e.g., private security), thereby inducing middle-class preferences for externalities-correcting public goods and their civic engagement in city politics. Thus, while segregation encourages the privatization of urban services, integration aligns the middle class with the poor in coalitions that support public goods. I illustrate how the argument applies to the location of streetlights, the extension of sewer lines, the stationing of policing units, and investments in public schooling. Drawing on focus groups from city cases, a proposed quasi-experimental strategy, and door-to-door survey of over 4,000 households across 420 neighborhoods in São Paulo, Brazil, this book project documents how patterns of urban geographies, by shaping opportunities for "exit" into private service provision, have major distributive and political implications for city politics.