Petrol expenditure and redistributive effects of its taxation in Spain

The objective of this paper is to estimate a petrol expenditure function for Spain and to evaluate the redistributive effects of petrol taxation. We use micro data from the Spanish Household Budget Survey of 1990/91 and model petrol expenditure taking into account the effect that income changes may have on car ownership levels, as well as the differences that exist between reported expenditure and real consumption during the week of reference. Our results show the importance that household structure, place of residence and income have on petrol expenditure patterns. We are able to compute income elasticities of petrol expenditure, both conditional and unconditional on the level of car ownership. Non-conditional elasticities, while always very close to unit values, are lower for higher income households and for those living in rural areas or small cities. When car ownership levels are taken as fixed, the conditional elasticity obtained is around one half the value of the non-conditional ones. As regards the redistributive effects of petrol taxation, we observe that for the lowest income deciles the share of petrol expenditure increases with income, and thus the tax can be regarded as progressive. However, after a certain income level the tax proves to be regressive.