What is the importance of business services decentralization in a Parisian metropolitan region known for its inherited monocentricity? Using revised statistical and cartographic methodological tools, I try to answer two debates: Is the new Parisian metropolitan economic geography one of dispersal or of polycentricity? Does decentralization mean the decline or the reinforcement of the economic core?
If secondary suburban economic centers benefit from business services decentralization trends, Paris City's neighboring spaces such as the Inner western suburbs of La Défense and Boulogne-Billancourt are affected too. This paper intends to demonstrate that polycentricity is not opposite to the constitution of a new golden triangle within the dense part of the agglomeration. This means both that economic centrality still matters (thus questioning that dispersed cities is the twenty-first century's metropolitan archetype), and that an enlarged CBD (Core Business District) straddling Paris and the western Hauts-de-Seine département, is being reinforced (thus invalidating CBD decline theory). Thanks to the widening of the business district from Paris to La Défense, the labor market remains an integrated one; meanwhile, secondary economic centers in the Outer Suburbs tend to create fragmented sub-regional labor markets of their own.