Sowell states that "no such theory has been found in even the most voluminous and learned histories of economic theories." That's from a scholar who has published extensively in the history of economic thought. Several years ago, Sowell, in his syndicated column, challenged anyone to name an economist from any economic school of thought who had actually advocated a "trickle down" theory. To date, no one has quoted any economist who ever advocated such a theory. Trickle down is a nonexistent theory. Those who use it simply argue against a caricature rather than confront an argument actually made.
President Barack Obama recently criticized Mitt Romney and Paul Ryan for trying to sell a tax plan, which he called "trickledown snake oil." Criticizing tax cuts as trickle down is a way not to confront the argument; however, there's empirical evidence about the effects of tax cuts. Sowell shows that during the Warren Harding administration, in 1921, Secretary of the Treasury Andrew Mellon advocated tax rate cuts, which were enacted into law by Congress. Afterward, there was rising output; unemployment plummeted; and the resulting higher income produced greater federal tax revenues, even though the tax rate had been lowered. There were somewhat similar results in later years after high tax rates were cut during the John F. Kennedy, Ronald Reagan and George W. Bush administrations.
The facts about the 1920s tax rate cuts are unmistakably clear for those who bother to check the facts. In 1921, when the tax rate on people earning more than $100,000 a year was 73 percent, the federal government collected a little more than $700 million in income taxes, of which 30 percent was paid by those earning more than $100,000. By 1929, after the tax rate had been cut to 24 percent on incomes higher than $100,000, the federal government collected more than $1 billion in income taxes, of which 65 percent was collected from those with incomes higher than $100,000.