How a progression clause affects the tax

Does that sound paradoxical? Perhaps. Behind this lies a question of justice. If someone has income that is considered tax-free, in principle only the remaining part of the income that falls under the tax liability is taxable. However, if the tax-free income is relatively high, this would mean that only a small part of the taxable income would remain. Accordingly, there would be a lower tax rate than for a person who has significantly higher income. The progression proviso is intended to change exactly that.