 A 2010 study documents the large extent to which U.S. taxpayers accelerate their deductible state tax income taxes by prepaying them in December, instead of their normally due January of the following year.In jurisdictions where tax rates are progressive – meaning that income taxes as a percentage of income are higher for higher incomes or tax brackets, resulting in a higher marginal tax rate – this often results in lower taxes paid, regardless of the time value of money.Tax-deferred retirement accounts exist in many jurisdictions, and allow individuals to declare income later in life; if the individuals also have lower income in retirement, taxes paid may be considerably lower.