This paper uses a single analytical framework in order to compare four measures of relative fiscal compliance and effort which have been used in the literature on the finance system of the Spanish Autonomous Communities. The comparison is empirically illustrated with reference to Spanish personal income tax. The use of income rather than product macroeconomic variables to determine the standard tax base, and the recognition of progressivity are shown to be important factors in determining the relative tax compliance and effort between Autonomous Communities.

Keywords: fiscal effort, fiscal federalism, tax progresivity.
JEL classification: H24, H26.