Thesis (M.C.P. and S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1999.Includes bibliographical references (leaves 167-176).The research couples accessibility models and demographic analyses to evaluate a modern interpretation of the spatial mismatch hypothesis as it applies to Boston, Massachusetts and San Juan, Puerto Rico. In relation to San Juan's new rapid rail line, Tren Urbano, the research evaluates alternative transportation services and land-use policies based on their ability to help welfare recipients and low-income workers reach employment. Empirical results show that concentrated poverty severely reduces low-income workers' job accessibility by forcing them to compete more intensely with one another for a limited supply of employment. In addition, results from Boston show that some aspect of race contributes very strongly to isolating low income workers, thereby creating relatively vast areas of highly concentrated poverty. Results from both cities indicate that employment concentrates toward the metropolitan center and that public transportation helps level the economic "playing field" for disadvantaged workers by enabling them to compete more effectively for employment outside low-income enclaves. In Boston, a city-to-suburb residential relocation program would be ineffective and might even reduce low-income families' quality of life by separating them from the social networks, services, densities of opportunity and transportation options available to them within the city. Rather, improving key transportation services seems to have a much greater potential for success. In San Juan, Tren Urbano will improve the physical job accessibility of all workers, though its social and geographic distribution of benefits will be inherently uneven. Tren Urbano will assist low-income workers living in outlying areas to reach jobs in the central city. Conversely, workers living near major employment centers will experience slight declines in their job accessibility as a result of increased competition. Welfare recipients, meanwhile, will experience an easier time reaching job locations but a slightly harder time gaining employment. The research identifies five key bus routes in San Juan, recommends adjustments to them, and proposes three specific cross-town services. It also recommends simple extensions of two existing routes, to serve roughly 30% of presently transit-isolated recipient households. Finally, policies that encourage residential relocation to Tren Urbano station areas from outlying regions have the greatest potential for improving individual recipients' access to jobs.by Clayton H. Lane.M.C.P.and S.M
