Sidewalk vendors occupy a peculiar place in contemporary urban landscapes. They are ubiquitous in many large cities of the world. Yet, they often maintain ambiguous positions in physical, cultural, political and socioeconomic spaces simultaneously. São Paulo, Brazil is no exception. My dissertation examines the ways camelôs, as vendors are often called in Brazil, navigate the material and symbolic spaces in which they operate. Focusing on the experiences, interactions, conversations and practices of a group of camelôs, the dissertation explores the relationship between work, identity, space and citizenship in contemporary São Paulo. I argue that the ambiguity engendered by camelôs' work practices and everyday experiences, in relation to various realms of social life, forces us to rethink the role of work in the formation of modern subjects and the obligations of the State in the contemporary world.

The dissertation illustrates how vendors' economic practices reside at the interstices of categories like legality and illegality, public and private space, employment and unemployment. In contrast to traditional understandings of an "informal economy" then, I suggest that the work practices of unlicensed sidewalk vendors in Brazil, and elsewhere, may be better understood as constituting a set of interstitial work practices.

The bulk of the dissertation explores how the liminal aspects of their work foster a constant uncertainty in vendors' everyday experiences, in spite of their relatively mundane labor routines. Descriptions of such routines provide the context to analyze the interactions camelôs have with each other, with pedestrian-clients, and with city agents—particularly police and tax collectors—and local governments who attempt to regulate their work. Contextualizing the research historically, the penultimate chapter sketches a genealogy of "interstitial work practices" in São Paulo and other Brazilian cities from colonial times through the 20^th century. The dissertation concludes by elaborating the concept of interstitial work further by considering unlicensed sidewalk vending as an economic, spatial, social, cultural, aesthetic, political and historically situated work practice. Furthermore, the final analysis paves the way for re-thinking studies on the informal economy as well as recent research on cities and citizenship that take struggles around housing as their primary focus.