The complex interplay between economic and political conditions and the nature and amount of informal economic activity, such as streetvending, has received little attention. This doctoral dissertation will examine the relationships between policies toward street vending, and degrees of economic stability, political stability, and the level of organization for political action among the streetvendors themselves. In particular, it will examine the nature of the conflict between streetvendors, city officials, and economic interest groups opposed to the presence of street trading in Mexico City, during two time periods, one of stringent regulation and one of an uneasy truce. Archival sources, newspaper reports, interviews with current and previous officials and streetvendor leaders, interviews with streetvendors, and ethnographic fieldwork in a few selected street market areas will be used to illuminate the process of the regulation of streetvending in one of the largest, fastest growing, and most congested cities in the developing world. This project will contribute to social scientific understanding of the political and economic factors shaping the construction and enforcement of regulatory policy. This project also will provide an excellent opportunity for a promising young scholar to continue to develop independent research skills.