Nouvelles centralités et valeurs immobilières. Une approche comparative des effets de centralité résidentielle à Bordeaux et Lyon

This study aims to identify emergent secondary centers within the Lyon and Bordeaux metropolitan areas and measuring their impact on residential real estate values, through the estimate of hedonic gradients. The various scales of the urban polycentrism are explored through the analysis of two types of subcenters: the emergence of secondary centers and the integration of satellite towns. The main subcenters are identified in both metropolitan areas using contiguity, job density and a minimum threshold for the number of jobs. The impact of subcenters on residential real estate values are estimated using semi-parametric hedonic models with three different specifications: a model with the distance to the main center and the nearest subcenter only, a polycentric model with the distance to every subcenters and a model of general accessibility to jobs rather than distance to subcenters. The results highlight the combination of two main trends to explain the recomposition of urban centrality: the effect of accessibility and amenities. The results suggest a ?decoupling? between the effect of amenities with immediate proximity to the centers and the effect of accessibility with a wider distance on both metropolitan areas. The main centers of Bordeaux and Lyon systematically induce a gradient with a break in slope that we interpret as the superposition of a gradient of amenity (with a steep slope) reflecting the enhancement of central amenities at immediate proximity to the center and a gradient of accessibility to employment, with a greater distance. This decoupling between gradients of amenities and accessibility can be compared to the usual distinction in environmental economics between a logic of exposure to amenities (which assumes immediate proximity) and a logic of accessibility to amenities.