The source: “Do Economists Agree on Anything? Yes!” by Robert Whaples, in The Economists’ Voice, Nov. ­2006.

“I’m tired of economists who say, ‘On the one hand . . . and then on the other hand,’” com­plained President Harry S. Truman when his fiscal advisers were waf­fling, as usual. “Send me a ­one-­armed economist.”

Today, Truman might get a straighter answer. Economists, despite appearances in the media to the contrary, overwhelmingly agree on a surprising number of issues, according to Robert Whaples, chair of the economics department at Wake Forest ­University.

They agree on free trade, the freer the better, Whaples found in a survey of 84 Ph.D.-holding econ­omists selected randomly from the ranks of the American Economic Association. Tariffs and agri­cultural subsidies should go, as should subsidies to professional sports fran­chises. Two out of three economists favor vouchers that parents can use for either private or public schools; four out of seven would junk the U.S. Postal Service’s remaining monopoly on mail delivery. Six out of 10 believe that the United States should broaden its use of nuclear power and increase energy taxes. Nearly half favor the elimination of the minimum wage. Eight out of 10 think that the gap between Social Security income and payout will become unsustainable in 50 years unless policies are ­changed.

Of four possible ways to fix Social ­Security—­raising the retirement age, cutting benefits, moving to mandatory personal accounts, or boosting payroll ­taxes—­there is widespread, if tepid, accord. More than 75 percent of economists agree that an increase in the retirement age (now 67 for those born after 1959) is the best plan, but very few “strongly agree.”

But even halfhearted consensus collapses over the impact of rising levels of greenhouse gases on the economy. On that issue, the economists’ views were scattered like birdshot. The largest single cluster of economists (36 percent) thought that allowing greenhouse gases to increase throughout the century would have little economic impact. About 21 percent of those surveyed thought that increased greenhouse gases might reduce gross domestic product by one to five percent. More than 16 percent thought that such a situation might increase GDP by the same amount. The issue, Whaples writes, is so complex that the question on greenhouse gases had the lowest response rate in the ­survey.

Most professional economists recognize that great swaths of economic turf have been conquered by one argument or another. But the public watching a televised debate between two economists on the elimination of the estate tax, for example, might wonder what most economists think, writes Whaples. More than 60 percent are opposed, but on the other hand, 35 percent are in ­favor.