We focus on the notion of borders to explore how mobility and immobility in the city affect the relationship between human development and urban culture. We define borders as a relational space made of territoriality, representations, and different possibilities of mobility and immobility. Drawing on research in the favelas of Rio de Janeiro, we suggest a systematic approach to the analysis of borders and identify the socio-institutional, spatial, and symbolic elements that make them more or less porous and thus more or less amenable to human mobility. We highlight the association between porosity in city borders and human development and illustrate the model contrasting two favela communities in Rio de Janeiro. We show that participation i...