Certain Effects of Uncertain Taxes

This paper explores the implications of tax rate uncertainty, identifying circumstances in which revenue-neutral tax rate variability increases profitability, economic activity, and the efficiency of resource allocation. Furthermore, with heterogeneous taxpayers, tax rate variability is shown to perform an efficiency-enhancing screening function, imposing heavier expected tax burdens on less responsive taxpayers. And while efficient tax uncertainty enables governments to reduce average costs of taxation, it necessarily increases the marginal cost of taxation over some ranges of expected revenue, so may reduce efficient levels of government spending.