The development of a migration model for England and Wales: overview and modelling out-migration
This paper reports the results of an extensive project to model interregional migration within England and Wales. The project took place over a two-year period and was sponsored by the UK Office of the Deputy Prime Minister (formerly the Department of Transport, Local Government and the Regions). The results of the study are reported in three separate papers. In this paper we present an overview of the project and then describe in detail both the process of modelling out-migration rates from origins across England and Wales and the calibration results from this modelling stage. The results yield important information on the determinants of out-migration and population re-distribution within England and Wales. In paper 2 we describe the modelling of the destination choices of migrants and the calibration results from such models. In paper 3 we tie both the out-migration and the destination choice results together into a mapping and visualisation system (MIGMOD) which can be used to assess the impacts of various policies on population movements in England and Wales. The simple policy scenarios reported in this third paper are illustrative and indicative of the model's potential, rather than necessarily being a true reflection of the effects of policy changes. The three papers contribute substantially to the existing migration literature because they present the most exhaustive analysis of the determinants of both out-migration and destination choice that has ever been undertaken. The number of variables in both modelling processes is far larger than has ever been assembled before and the results therefore provide much greater insight into the role of various attributes in determining out-migration rates and in-migration rates than has previously been possible. The papers also provide an interesting lesson in a problem rarely encountered -- that of having too much data.