When people evade income taxes by not declaring taxable income, a vicious cycle results  Tax evasion forces lawmakers to raise income tax rates, which causes the tax burden on nonevading taxpayers to become heavier
This, in turn, encourages even more taxpayers to evade income taxes by hiding taxable income
Some methods for detecting tax evaders, and thus recovering some tax revenue lost through evasion, bring in more than they cost, but their success rate varies from year to year.