Multiplex approaches of Urban systems in multinational firms' networks

This paper revisits the conceptual and methodological bases of networks approaches used for twenty years to study spatial processes that link cities and multinational companies, and that are now widely deployed in the literature on ''global cities''. The aim is to explain the choices at each step of the process, often remaining implicit, and their implications in the results. Starting with multilevel and multidimensional relationships involved in city business networks of multinational companies, it examines the intrinsic links between mobilized concepts and constructed networks in empirical studies. Two levels of assumptions are explained: firstly, the assumptions made from the networks themselves which conditions the definitions of interactions, and secondly, those made in the dimensions of the built objects, positioning cities and enterprises in various central positions. The article proposes an actor-network perspective based on the ''multiplex'' network approach.