Accessibility and Development in Portuguese Off-cost Regions: a Spatial Regression Analysis
A Ribeiro, A Antunes, University of Coimbra, PT
Using an autoregressive model we found that new accessibility (due to Portuguese new roads) contribution to development is poor or null when confronted with literacy levels and changes substantially accordingly to the spatial scale.
During the last twenty years, the main road network of Portugal underwent a profound transformation, particularly important for the off-coast depressed region close to the Spanish borderline. The new, fast roads built there in the late 1980s and early 1990s completely changed the accessibility conditions. This makes off-coast Portugal a perfect setting for the analysis of a matter that deserves a deeper debate in the planning literature i.e. the relationship between accessibility and spatial development. In previous research and for a set of 86 municipalities in this region, we found that accessibility contribution for development (how its increase affects population growth) is poor or null when confronted with population literacy levels, in an autoregressive spatial analysis environment. In the spatial models estimated, heterogeneity is still present, which might compromise the relation between the explanatory variables and the dependent variable over the complete dataset. Among other spatial regression analysis techniques, Spatial Regimes is able to account for this heterogeneity, by means of switching regression models. When different subsets in the data correspond to spatial clusters or regions with special characteristics, the Spatial Regimes specifications adds important information to this innovative application of spatial econometric analysis: the relationship between accessibility and spatial development. In fact, this relationship differs when using different subsets of data when compared with previous results for the complete dataset. The way transport infrastructures and accessibility affects local development, changes substantially accordingly to the spatial scale under this type of group wise estimation. These facts underline the importance of selective infrastructures policies within the national and regional context.
Association for European Transport