How far do internal migrants really move?:Demonstrating a new method for the estimation of intra-zonal distance

This paper makes use of data on origin to destination migration by postcode derived from a large biannual consumer survey, Acxiom’s Research Opinion Poll, to measure distances of migration within England in the mid-2000s. These data provide an opportunity to evaluate conventional methods of centroid-based estimation of inter-zonal distance and area-based estimation of intra-zonal distance, and demonstrate how the latter in particular generates problematic estimates. A new regression-based approach for generating intra-zonal distance is presented, resulting in significantly improved goodness-of-fit statistics when used in doubly constrained spatial interaction modelling of migration flows for local authority districts in England from the 2001 and 2011 Censuses