Biggs on Bracket Creep
If the tax cuts expire, income-tax revenues by 2018 will rise to 10.8% of the total economy from 8.7% today – an increase of 24%. Compared to the average over the last 50 years, allowing the rates to rise would increase tax revenues by 32%.
Believe it or not, income taxes will rise even if the tax cuts remain in place, because the revenue-increasing effects of bracket creep more than offset the lower rates. With the lower rates, total income-tax revenues will increase to 9.3% of GDP by 2018. This level is 7% higher than today, and 13% above the 1957-2007 average. Thus even with the tax cuts, revenues will increase by more than enough to fix Social Security.
What is truly frightening is that even these tax increases are not sufficient to pay for Medicare.