Is cities delineation a pre-requisite for urban modelling? The example of land price determinants in Brussels

This paper assesses the usability of land prices as an indicator of the efficiency by which different delineations of a given city capture the influence area of that city. The case study used is Brussels (Belgium). A hedonic model of land prices (log-linear and semi-parametric specifications) is estimated for 12 different delineations of the city and on automatically constructed delineations. The assumption, grounded in the Alonso-Muth model, is that when local amenities have been controlled for, accessibility to the CBD parameter estimate will reflect the city influence on its delineation. Results show that both the size and composition of the delineations of Brussels influence the land price determinants. The size changes the spatial structure of land prices, which is best described by Hoyt’s sector model for narrow definitions of Brussels, and by Alonso-Muth type model for larger definitions. Composition induces variations in the magnitude of the influence of accessibility to the CBD on land prices, due to the presence of secondary centers or rural areas. The lack of detailed data on land prices limits the robustness of the results. Nevertheless, our findings show the potential of land prices as a tool for comparing delineations of a city, or to draw delineations of that city. Finally, they also suggest that delineations based on fluxes (e.g. commuting), and on endogenous thresholds, are more adequate to capture the influence area of a city than those based on transport infrastructure or administrative delineations