Can the Progressivity of Tax Changes Be Measured in Isolation?

Several nonprofit groups such as the Tax Policy Center and Citizens for Tax Justice as well as several governmental entities provide tables on the distributional effects of tax changes. Analysts then suggest that these tax cuts are progressive, proportional or regressive by comparing such measures as the percentage change in after-tax income for different income classes. To know the effect of tax changes on the distribution of income, it is necessary to take into account what the government does with the money.