Abstract In this paper the effect of tax harmonization on intergovernmental expenditure competition is analysed. To this end, it is assumed that self-interested governments cannot influence tax rates, since taxes are harmonized, but that they can freely choose expenditure
policies and, by this, attract additional capital and broaden the assessment base of a capital tax. Hence, self-interested governments might have a financial incentive to provide for public input besides re-election oriented motivations. Since additional tax income from public input provision
depends on the harmonized capital tax rate, the choice of the tax rate indirectly determines the amount of public input supplied by governments in expenditure competition.