The work of the new supply-siders shies away from the old claims that low taxes will generate an explosion of entrepreneurship or extra hours on the job. Instead, it just looks at the data. When top marginal rates fell, as they did under President Ronald Reagan in 1981 and 1986 or under President Bush in 2001 and 2003, taxpayers whose rates declined the most reported the biggest increases in income in the following years. The supply-side advocates attribute those gains to tax cuts and argue that the Laffer curve — which suggests that some tax cuts can pay for themselves — may live yet.
Some of the most important research was done by Lawrence B. Lindsey, former head of the National Economic Council under President Bush and now the senior economic adviser to the Republican presidential contender Fred D. Thompson. But the origins of the current debate, and the seriousness with which it is taken in academic circles, largely center on the work of the Harvard economist Martin Feldstein.
Professor Feldstein, head of the National Bureau of Economic Research, is perhaps the godfather of modern public-sector economics and is often cited as a potential Nobel laureate. The former chairman of President Reagan’s Council of Economic Advisers, he has always been known for his conservative views. He has brought more comprehensive data to bear and has made the most influential case; if you accept the evidence he offers, progressivity in the tax code appears very damaging. Raising taxes on high-income people seems to make the economy much less efficient and raises little revenue.
As he put it in a 2006 interview published in a magazine of the Federal Reserve Bank of Minneapolis, when you raise top marginal rates, “it shows up as lower taxable income.” He added: “A reduction in taxable income, whether it occurs because I work less or because I take my compensation in this other form, creates the same kind of inefficiency.”
But for all the renewed interest in supply-side ideas, the politicians espousing these views have missed three important points that have come out of the continuing academic debate...
Second, other research has shown that the new supply-side movement missed a fundamental shift over the last 30 years — the dramatic, disproportionate rise in the compensation of high-income people. The new supply-siders have confused this shift with the impact of tax cuts.
An example illustrates the point: Emmanuel Saez, a professor of economics at the University of California, Berkeley, has compiled data on the incomes of the very rich from 1913 to 2006. Using his data, my calculations show that in the four years after top marginal rates were cut in 1981 and 1986, and in the three years after the rate cut of 2003, average real salaries (subtracting inflation) for the top 1 percent of earners grew 18.8 percent, 22.5 percent and 17.4 percent. But for the bottom 90 percent of earners over those periods, the average salary changes were 2.6 percent, minus 0.3 percent and minus 0.1 percent. A supply-sider might see this as evidence of the growth power of cutting top rates.
But the data also show that incomes at the top have been growing rapidly regardless of what happened to tax rates. In the four years after the increase in top marginal rates in 1993, average salaries grew 18.7 percent among the top 1 percent of earners and less than 0.1 percent for the bottom 90 percent.
Seeing the same pattern when taxes rose as when they fell indicates that tax cuts weren’t responsible. It suggests that cuts for high-income taxpayers likely gave windfalls to those whose incomes were already rising sharply because of broader market forces.
-Is the New Supply Side Better Than the Old?