The past 35 years or so have seen a persistent history with regard to federal tax revenues. Republicans, who have dominated the federal government for most of that time, have cut the taxes that fall more heavily on businesses and the wealthy, the personal and corporate income tax. And then following a fiscal disaster and soaring deficits, Democrats increased those same taxes. In the end the personal income tax ended up, as a percent of GDP, about where it was – at 8.1% of GDP in FY 2014 compared with 7.9% of GDP in FY 1978. While the corporate income tax ended up lower, at 1.9% of GDP compared with 2.6%. This is true even though profits account for a higher share of GDP today than they did in 1978, and work earnings at the top account for a much higher share of total earnings, factors that should have increased personal and corporate income tax revenues as a percent of GDP even with the exact same rules.
Payroll taxes, meanwhile, were substantially increased by the Republicans and never reduced, save for a special exemption in the Great Recession. These taxes fall exclusively on work income in the United States, and more heavily on the working and middle classes. The wealthy pay less, as a percent of their income, the retired do not pay at all and, with regard to international trade, work done in the United States is subject to the tax whereas goods imported from abroad are tax-free. The payroll tax burden increased from 5.3% of GDP in FY 1978 to 6.5% in FY 2001. Before falling to 5.9% in FY 2014, after the share of Americans working and average work income plunged in the Great Recession. Other federal revenues, such as excise taxes, estate taxes, and customs duties totaled 1.7% of GDP in FY 1978 and 1.6% of GDP in FY 2014, although the composition of this category has changed. These trends are discussed in more detail below.