SPAG: Index of spatial agglomeration

The paper develops a spatial agglomeration index (SPAG) of the economic activity for the point geo‐localizations of firms. It includes the effects of location, the distance between firms and the overlapping impact of the firms' size. The SPAG builds a new class of measures of the spatial density of the economic activity inside the region, based on the geometrical representation of firms with circles, without referring to the commonly used Ripley's K function. The SPAG measures the degree of divergence from the benchmark distribution, what detects different spatial distributions as clusters or borderline dispersion. We test SPAG with real point data.