Distribution of jobs and identification of business centers: a non-parametric approach.

Summary We study the distribution of jobs in the Lille metropolitan area in order to identify the main business centers and characterize the urban form of this agglomeration. The aim is not only to identify the municipalities with high levels of employment, but also those that have a significant influence on the distribution of jobs. Our results confirm the polycentric structure of the Lille conurbation, and we find that the municipality of Roubaix (sometimes accompanied by Tourcoing) stands out as being highly central. On average, a distance of one kilometer from a business sub-center decreases the employment density by nearly 20%. The identification of business sub-centers is important because these employment zones influence the location decisions of economic actors, and are therefore to be taken into account in the development of urban policies. The technical difficulty consists in separating the effect of the city center (the main business center) from the effect of the multiple sub-centers. As our empirical application reveals, nonparametric approaches are more effective than parametric ones.