On the link between rail transit and spatial income segregation

The link between transportation infrastructure and income segregation has long been recognized in the literature, but has received renewed attention with the increased investment in rail transit in US cities. In this paper, we examine the impacts of rail transit investments on neighborhood income diversity and metropolitan income segregation. For the neighborhood-level analysis, we apply a difference-in-difference approach combined with propensity score matching in 11 metropolitan areas that invested in rail transit between 2000 and 2005. We then estimate the effect of changes in rail transit access on income segregation across the 50 largest metropolitan areas in the US between 1990 and 2010. We find no statistical evidence that rail transit investments spur changes in neighborhood income diversity when compared to similar neighborhoods elsewhere in the city. Similarly, we find no significant impact of new or expanded rail transit lines on metropolitan wide income segregation