The Laffer Curve in the 1920s
During the 1920s, The Revenue Acts of 1921, 1924, and 1926 reduced the top marginal income tax rate from 73% to 25% (see top chart, blue line). Did the drastic cut in tax rates cause tax revenues to fall? No, just the opposite. Personal income tax revenues increased substantially during the 1920s, rising from $719 million in 1921 to $1.16 billion in 1928 (see top chart, red line), an increase of more than 61% (this was a period of no inflation).
The share of the tax burden borne by the rich rose dramatically. As seen in the bottom chart above, taxes paid by the rich (those making $50,000 and up in those days) climbed from 44.2% of the total tax burden in 1921 to 78.4% in 1928.
Source: Heritage Foundation, "The Historical Case for Supply-Side Economics," by Dan Mitchell
Bottom Line: The significant cuts in marginal income tax rates in the 1920s increased tax revenues collected, and the share of taxes paid by "the rich" increased.