Like most European and North American metropolitan regions, that of Paris has for several decades been subject to a set of transformations. These have concerned urban spatial structures (population deconcentration, dispersion of employment, and the growth of new economic poles in the peripheral area), but also the sociodemographic structure of the population (rise in female labour participation rates, increasing importance of a highly qualified high-earning population, etc), and individual behaviour (desire for homeownership as well as the renewed interest of affluent groups for city-centre living, etc). Increased daily mobility in general and commuting in particular cannot be explained without reference to these different phenomena operating at both the microlevel and the macrolevel. For example, the sociodemographic characteristics of individuals have a considerable influence on the probability of the individuals being able to work near their home (or to live near their workplace). Account also has to be taken of the residential strategies of individuals, which are in turn linked to social position and life-cycle stage: choosing a place of residence in the urban periphery, in particular, has an impact on commuting patterns. But we can only understand the effects of residential strategies on commuting by analyzing the structures of the Île-de-France region (and in particular the housing market and sociogeographical pattern of employment).