A preliminary investigation of the stability of Geographically-Weighted Regression

This paper describes preliminary work analysing the stability of parameter coefficient estimates for Geographically-Weighted Regression (GWR). Based on a large dataset (35721 points) various random samplings of this data were performed and models built using GWR. An analysis of the coefficient values for the independent variables showed that these values could varying significantly both between runs and between sampling sizes. This suggests that the results from GWR must be carefully considered in terms of the form of data, assumed coefficient surface being modelled, and the confidence of the resulting parameter estimates.PublishedNon Peer ReviewedBayley, A. & R. Goodyear (2001) An Urban/Rural Profile, Statistics New Zealand, . Brundsdon, C., A. S. Fotheringham & M. Charlton (1996) Geographically weighted regression: A method for exploring spatial nonstationarity. Geographical Analysis, 28: pp. 281-289. Farber, S. & A. Paez (2007) A systematic investigation of cross-validation in GWR model estimation: empirical analysis and Monte Carlo simulations. J. Geograph Syst, 9: pp. 371-396. Fotheringham, A. S., C. Brunsdon & M. Charlton (2002) Geographically Weighted Regression: the analysis of spatially varying relationships, John Wiley & Sons, Ltd, . Hay, G., P. Whigham, K. Kypri & J. Langley 2007, 'Spatial variation in the association between neighbourhood deprivation and access to alcohol outlets', in Proceedings of the 19th Annual Colloquium of the Spatial Information Research Centre, Ed P. Whigham, Otago University Print, Dunedin, New Zealand. Ihaka, R. & R. Gentleman (1996) R: A Language for Data Analysis and Graphics. Journal of Computational and Graphical Statistics, 5:3, pp. 299-314. Martin, D. (1989) Mapping Population Data from Zone Centroid Locations. Transactions of the Institute of British Geographers, 14:1, pp. 90-97. Pearce, J., K. Witten & P. Bartie (2006) Neighbourhoods and health: a GIS approach to measuring community resource accessibility. J Epidemiol Community Health, 60: pp. 389-395. Salmond, C. & P. Crampton 2002, NZDep Index of Deprivation, Department of Public Health, Wellington School of Medicine and Health Sciences, City,