Criticism
Critics of supply-side economics pointed to the lack of academic economics credentials by movement leaders such as Jude Wanniski (bachelor's degree in political science and a master's degree in journalism from the University of California, Los Angeles) and Robert Bartley (bachelor's degree in journalism from Iowa State University and a master's degree in political science from the University of Wisconsin) to imply that the theories were bankrupt. Mundell in his Nobel Prize lecture (awarded for unrelated work in optimum currency area) countered that the success of price stability was proof that the supply-side revolution had worked. The continuing debate over supply-side policies tends to focus on the massive federal and current account deficits, increased income inequality and its failure to actually promote growth.
Many critics of supply-side economics are actually critics of politicians and pundits who misunderstand the Laffer curve, typically claiming that every tax cut will increase revenues. For example, in 2006 Sebastian Mallaby of The Washington Post quoted George W. Bush, Dick Cheney, Bill Frist, Chuck Grassley, and Rick Santorum misstating the effect of the Bush Administration's tax cuts. On January 3, 2007, George W. Bush wrote an article claiming "It is also a fact that our tax cuts have fueled robust economic growth and record revenues." Andrew Samwick, who was Chief Economist on Bush's Council of Economic Advisers from 2003-2004 responded to the claim:
You are smart people. You know that the tax cuts have not fueled record revenues. You know what it takes to establish causality. You know that the first order effect of cutting taxes is to lower tax revenues. We all agree that the ultimate reduction in tax revenues can be less than this first order effect, because lower tax rates encourage greater economic activity and thus expand the tax base. No thoughtful person believes that this possible offset more than compensated for the first effect for these tax cuts. Not a single one.
Only cutting tax rates to the right of the Laffer curve's peak rate will increase revenues. Cutting tax rates to the left of the peak rate will decrease revenues. Depending on the model and values of variables that are used, some have estimated the peak rate to be between 60-80% for labor tax and 50-60% for capital tax
Some politicians and supply-side advocates may misunderstand the Laffer curve. They claim that every tax cut will increase revenues, when the curve clearly shows that only cutting tax rates to the right of the peak rate will increase revenues. Cutting tax rates to the left of the peak rate will decrease revenues. Since Reagan's income tax cuts in the 1980s did not increase receipts, the Laffer curve would suggest that further tax cuts will not increase revenues either, since the economy is apparently to the left of the peak. The Bush administration has been reporting record revenues, however those are, once again, coming from FICA taxes, not the income taxes which were cut. Between 2000 and 2004, income tax revenues fell from $1,004.5 billion to $809 billion, while FICA tax revenues increased from $652.9 billion to $733.4. Since 1997, the US Treasury has been reporting the combination of income tax and FICA tax revenues, so decreases in income tax revenues are hidden by increases in FICA tax revenues. Depending on the model and values of variables that are used, some have estimated the peak rate to be between 60-80% for labor tax and 50-60% for capital tax
The paradigm of a tax system which rewards investment over consumption was accepted across the political spectrum, and no plan not rooted in supply-side economic theories has been advanced in the United States since 1982 (with the exception of the Clinton tax increases of 1993) which had any serious chance of passage into law. In 1986, a tax overhaul, described by Mundell as "the completion of the supply-side revolution" was drafted. It included increases in payroll taxes, decreases in top marginal rates, and increases in capital gains taxes. Combined with the mortgage interest deduction and the regressive effects of state taxation, it produces closer to a flat-tax effect. Proponents, such as Mundell and Laffer, point to the dramatic rise in the stock market as a sign that the tax overhaul was effective, although they note that the hike in capital gains may be more trouble than it was worth.
Cutting marginal tax rates can also be perceived as primarily beneficial to the wealthy, which commentators such as Paul Krugman see as politically rather than economically motivated.
The 1990s
Supply-siders blame the 1991 recession on the Federal Reserve, and argue that Clinton's tax increases, since they did not change marginal capital gains tax rates, left the supply-side nature of the 1986 tax bill in place. Similarly, supply-side economists have argued that since the early phases of the massive tax breaks of George W. Bush's first two years were based on credits and not cuts in marginal rates, they did not act to stimulate the economy, although the effect on individual income remains the same.
More generally, traditional economists point to the "overhang" of deficits from the Reagan era, the S&L bailout, the effects of a ballooning federal budget deficit, the defense budget cuts which began in earnest in 1989, and the expectation of a lack of continued fiscal discipline as the source of the recession. These arguments blame the legacy of Democratic Deficits forced upon Reagan, rather than deficits created by Reagan's own administration. Critics of supply-side economics often argue the inflated government deficits that accompanied the arrival of supply-side economics are of greater concern than the economic and stock market success of supply-side theory.
A Trojan Horse
Stronger critiques of supply-side economics dismiss the entire project as a Trojan horse for reducing marginal tax rates on upper income brackets and ultimately a failure. These critiques are found in Samuel Bowles' work, which argues that real productivity fell under supply-side taxation regimes on a unit-worker basis. Paul Krugman of Princeton called supply-side economics "Peddling Prosperity" and dismissed it as being unworthy of serious economists in a 1994 book written for the general audience.


