Abstract : Many claims are made about the relative influence of formal institutions, market-driven interests, and elements of culture in explaining behavior sitting astride the frontier between the worlds of “politics” and “business". This paper proposes both to blur disciplinary boundaries and to move toward more explicit hypothesis testing through a dual comparison of national and sectoral cases. It examines two policy areas – environmental protection and housing affordability – in two medium-sized urban areas – greater Montpellier in France and greater Denver in the United States. This research design of this kind allows the paper to test the relative influence of national and local institutional, interest-based, and cultural variables in a coherent and systematic fashion. We conclude that national-level differences between France and the US are surprisingly small in light of seemingly great institutional and cultural differences. At the local level, both national cases exhibit considerable internal variation in policy choices at the municipal level. These choices are better explained by reference to local political choices crystallized over time into patterns of land use and property ownership than they are by invoking contemporary economic interests.