The penalty on risky personal income due to tax rate progression

This paper analyzes the tax penalty on volatile personal income under progressive tax rates. The phenomenon may have an effect on long-term entrepreneurial decisions as well as risky occupational choice. An options-based model is used to estimate the expected effective rate due from tax-payers at different income levels and volatilities under the current Czech legislation. A comparison is made to the system which has been in place until 2005, as well as to the Slovak flat-rate schedule. The model shows that volatile incomes incur a substantial penalty of up to 2 percentage points on the effective rate peaking just below the official income statistics mean. The effect is more pronounced than under the former parameters of the tax code. A severe impact on below-average earners due to the mandatory minimum tax-base regulation has been demonstrated. On the other hand, the Slovak flat tax with a single marginal rate bears virtually no sensitivity to income volatility, with the slight exception of very low incomes.

Keywords: income tax, option model, tax rate progression, personal income, income volatility, risk-taking, occupational choice