Prices, taxes and automotive fuel cross-border shopping

The aim of the present paper is to determine whether differences in automotive fuel prices among neighboring Autonomous Communities (i.e. Spanish political-administrative regions) affect the decisions taken by individuals regarding the region in which to purchase fuel. In particular, the intention is to discover if price increases in certain Autonomous Communities, as a result of the application of the regional tranche of the Hydrocarbon Retail Sales Tax (HRST) has affected fuel purchases in neighboring Communities.In order to achieve the above-mentioned objectives, the monthly purchases of automotive diesel in Aragon between January 2001 and March 2007 is estimated from the fuel price in Aragon, the relation between prices in each of the bordering Communities and Aragon, weighted by density of traffic, the number of vehicles registered in that Community, and three dummy variables representative of the implementation of the regional tranche of the HRST in Madrid, Catalonia, and Valencia. The paper finds empirical evidence to demonstrate a positive effect of the relative prices in the neighboring Communities and vehicle registrations, and also a negative effect of prices in Aragon, upon the acquisition of diesel in this region. In the case of Catalonia, some evidence suggests that the price effect may have been strengthened following the introduction of the regional tranche of the HRST in August 2004.