Measuring spatial concentration of the population: a new approach

Augusto Ascolani, Università di Trento
Giuseppe Espa
Rossella Baldini

Abstract Standard disparity measurements, like locational indices or relative variance indicators, are used to describe the territorial aspect of spatial concentration of the population. These indices do not contain any reference to the location of observed statistical units (regions), exclusively measuring the a-spatial aspects of concentration. The study of spatial concentration can not leave out of consideration “where” the regions are located, that is polarisation. Therefore it is required to examine jointly the a-spatial aspect (usually measured by Gini index) as well as the polarisation one, appropriately measured by the spatial correlation coefficient (like Moran index). The a-spatial concentration and the polarisation are substantially the indissoluble components of the geographic concept of concentration. The present paper proposes a methodology that achieves this aim with reference to italian population at last Census level.