Operational Local Join Count Statistics for Cluster Detection

J Geogr Syst. 2019 Jun;21(2):189-210. doi: 10.1007/s10109-019-00299-x. Epub 2019 May 2.

Abstract

This paper operationalizes the idea of a local indicator of spatial association (LISA) for the situation where the variables of interest are binary. This yields a conditional version of a local join count statistic. The statistic is extended to a bivariate and multivariate context, with an explicit treatment of co-location. The approach provides an alternative to point pattern based statistics for situations where all potential locations of an event are available (e.g., all parcels in a city). The statistics are implemented in the open source GeoDa software and yield maps of local clusters of binary variables, as well as co-location clusters of two (or more) binary variables. Empirical illustrations investigate local clusters of house sales in Detroit in 2013 and 2014, and urban design characteristics of Chicago census blocks in 2017.

Keywords: LISA; join count statistic; multivariate spatial association; spatial clusters; spatial data science.