Achieving data compatibility over space and time: creating consistent geographical zones

The importance of boundary specification and problems with using arbitrarily defined subnational areas for the collection and dissemination of socioeconomic data are widely recognised. Much research has focused on the modifiable areal unit problem and on custom zone design, but the practical difficulties created by temporal inconsistencies in zonal boundaries have received less consideration. The UK experiences frequent administrative boundary changes causing difficulties in producing comparable statistics through time. Unless a consistent geographical approach is taken with time‐series data, it cannot be known whether changes in the relationships between variables collected for areas at different points in time are real or an artefact of boundary changes. After illustrating the nature of the boundary change problems to be overcome, this paper appraises strategies that can be adopted and develops a method by which time‐series data can be established on a consistent geographical basis. Copyright © 2003 John Wiley & Sons, Ltd.