LAUSR

Higher wages in agglomerations often do not reflect an increase in purchasing power, because a high percentage of the wage increase has to be spend on housing. Thus, after housing is considered taxpayers may have identical disposable incomes, although gross as well as after-tax income may differ. This unequal treatment of taxpayers is due to the taxation of nominal incomes. If tax systems taxed income based on regionally adjusted purchasing power, horizontal equity would be assured. Since this is an unfeasible option, the differences could be corrected by allowing a deduction on housing costs. Given the large revenue losses, it seems unlikely that governments in OECD countries move to a system where rents are deductible in determining taxable income. Another alternative—taxation of potentially achievable income—is unfeasible due to political opposition. A final and less costly alternative is fiscal federalism. Granting autonomy to the lower levels of the government offers local governments the power to design the tax system in a way that reflects differences in living costs. Although this option does not necessarily imply that governments effectively design the tax schedule in that way, a comparison of Germany and Switzerland shows that governments are aware of these differences across regions. The paper concludes that granting tax autonomy to the lower tiers in Germany would make many citizens, especially in the Southern part, better off and would promote horizontal equity among German taxpayers.