Robert Samuelson of the Washington Post devotes his latest column to clearing up the latest of Paul Krugman’s economic errors.

It’s important to get history right — and economist and New York Times columnist Paul Krugman has got it maddeningly wrong.

Krugman recently wrote a column arguing that the decline of double-digit inflation in the 1980s was the decade’s big economic event, not the cuts in tax rates usually touted by conservatives. Actually, I agree with Krugman on this. But then he asserted that Ronald Reagan had almost nothing to do with it. That’s historically incorrect. Reagan was crucial.

In nearly four decades of column-writing, I can’t recall ever devoting an entire column to rebutting someone else’s. If there were instances, they’re long forgotten. But Krugman’s error is so glaring that it justifies an exception. It’s also a subject about which I know something, having written a book on it: “The Great Inflation and Its Aftermath: The Past and Future of American Affluence.” This column draws from that book. …

… Krugman’s story is simple. The Fed is “largely independent of the political process” and, under chairman Paul Volcker, “was determined to bring inflation down,” he wrote. “It tightened policy, sending interest rates sky high, with mortgage rates going above 18 percent.” The result was “a severe recession that drove unemployment to double-digits but also broke the wage-price spiral.”

Indeed. By 1982, the gain in consumer prices had dropped to 3.8 percent. Volcker crushed inflation.

Story over? Not really.

What Reagan provided was political protection. The Fed’s previous failures to stifle inflation reflected its unwillingness to maintain tight-money policies long enough to purge inflationary psychology. Successive presidents preferred a different approach: the wage-price policies built on the pleasing (but unrealistic) premise that these could quell inflation without jeopardizing full employment.

Reagan rejected this futile path. As the gruesome social costs of Volcker’s policies mounted — the monthly unemployment rate would ultimately rise to a post-World War II high of 10.8 percent — Reagan’s approval ratings plunged. In May of 1981, they were 68 percent; by January 1983, 35 percent.

Still, he supported the Fed. “I have met with Chairman Volcker several times during the past year,” he said in early 1982. “I have confidence in the announced policies of the Federal Reserve.”

This patience enabled Volcker to succeed, though it took about two years of tight money. It’s doubtful that any other plausible presidential candidate, Republican or Democrat, would have been so forbearing.