The IRS adjusts tax brackets based on a measure of inflation in the U.S. economy. Because the cost-of-living increases, tax brackets change, along with the amount of the standard deduction and other adjustments. The tax reforms of the Tax Cuts and Jobs Act of 2017 changed the measure used by the IRS from reflecting urban consumers to reflecting the so-called chained consumer price index, which results in smaller upward changes to deductions and tax brackets.