Measuring and testing spatial mass concentration with micro-geographic data

We address the question of measuring and testing industrial spatial concentration based on micro-geographic data with distance based methods. We discuss the basic requirements for such measures and we propose four additional requirements. We also discuss the null assumptions classically used for testing aggregation of a particular sector and propose an alternative point of view. Our general index measure involves a cumulative and a non-cumulative version. This allows us to propose an alternative version of the Duranton Overman index with a proper baseline as well as a cumulative version of this same index. We illustrate the approach with some simulated data.