The U.S. economy contracted by a steep 6.3 percent in the fourth quarter last year, and more than 5 million jobs have vanished since December 2007. Still, most financial experts believe the nation is unlikely to plunge into the dizzying economic depths of the 1930s, when double-digit unemployment rates and soup lines were the norm.

They point out that senior policymakers today, ranging from Federal Reserve Chairman Ben Bernanke to Christina Romer, chairwoman of the White House Council of Economic Advisers, have devoted their academic careers to studying the cataclysmic mistakes committed by President Herbert Hoover when he backed steep tariffs in 1930 that choked off international trade and approved a major tax increase in 1932.

In addition, while many historians revere President Franklin D. Roosevelt for offering despairing Americans a glimmer of hope with his New Deal, a number of economists argue that much of his economic program retarded, rather than promoted, a recovery.

"We're not necessarily likely to repeat the Great Depression," said Amity Shlaes, author of the 2007 best-selling book The Forgotten Man: A New History of the Great Depression.

"But what happened in the Depression still matters," she said. "That's because some of the steps Hoover and Roosevelt took made the Depression great, so we want to avoid repeating those errors."

Allan Winkler, a professor of history at Miami University and an admirer of the New Deal, acknowledged that "One of the problems was that there were so many conflicting elements of the New Deal it never really was a fiscal stimulus."

Some economists, however, fear that President Barack Obama may tread too closely to Roosevelt's fundamental distrust of free markets, opting to prop up inefficient industries and promoting the same type of tax increases championed 75 years ago by Hoover and Roosevelt.

"I'm worried that a significant part of the population has the idea that markets can't be trusted," said Lee E. Ohanian, professor of economics at UCLA. "That's exactly the idea that you saw in the 1930s. I am hopeful that policymakers will recognize the importance of raising incentives and not raising tax rates on the most productive of people."

By virtually any standard of postwar America, today's economic numbers are bleak. The unemployment rate has climbed to 8.5 percent; housing prices have dipped precariously from their peak in the middle of the decade; foreclosures have spread throughout the country; and General Motors and Chrysler are close to collapse.

But today's economy does not match the horrors of the Great Depression -- that's "like comparing a rainstorm to Katrina," said Shlaes. In 1932, one in four workers were jobless, more than 40 percent of Ohio's factory workers were out of work, and half the industrial workers in Cleveland had lost their jobs.

"The current recession, while unquestionably severe, pales in comparison with what our parents and grandparents experienced in the 1930s," Romer last week told a Senate subcommittee chaired by Sen. Sherrod Brown, D-Ohio.

But today's recession has rekindled an intense debate among economists and historians about Roosevelt's economic policies. Brown devoted all of last week's hearing to the New Deal. Of the five witnesses, four hailed Roosevelt's actions for reducing the misery of the Great Depression.

The debate is more than just a quaint academic exercise. Obama speaks approvingly of Roosevelt and favors concepts that have their roots in the New Deal: more federal spending for roads, bridges, health care and the environment. By contrast, Republicans want to curb federal spending and keep tax rates as low as possible.

Because of the New Deal and its litany of alphabet programs -- from the FDIC to the WPA to the SEC -- Americans are far better protected from the negative effects of the marketplace.

The Federal Deposit Insurance Corp. insures large chunks of individual savings accounts. Social Security cushions the elderly against the ravages of poverty. The unemployed get financial benefits, and the Securities and Exchange Commission attempts to impose order on the financial system.

Roosevelt poured as much as $100 billion (in 2009 dollars) into programs such as the Works Progress Administration, which provided jobs to millions of unemployed Americans. WPA workers helped build or renovate 2,500 hospitals, 45,000 schools, 700,000 miles of roads, 7,800 bridges and 1,000 airfields.

But other aspects of the New Deal seemed to work at cross-purposes. The National Industrial Recovery Act, eventually struck down as unconstitutional by the Supreme Court, allowed companies to collude on prices provided they paid higher wages.

The Wagner Act of 1935 gave organized labor greater powers in its struggle for higher wages, prompting some economists to contend that the two laws artificially boosted wages and prices at a time when lower prices would have encouraged consumption.

"All this stuff with the NIRA was destructive, and it's hard to find a reputable economist who doesn't believe that's true," said Paul Evans, a professor of economics at Ohio State University. "Most of the dumb things that the Roosevelt administration did, Obama's (advisers) know they were dumb. So we're not repeating those mistakes."

Economists who believe in the New Deal also argue that if anything, Roosevelt was too worried about a federal deficit to boost the economy through more spending and less taxes. Taxes on the wealthy remained steep during the 1930s, which meant the government was taking as much money out of the economy as it was inserting with work programs.

"The emergency spending that Roosevelt did was precedent-breaking," Romer told Brown's panel. "But it was quite small."

By contrast, Romer pointed out that Obama pushed through Congress a $787 billion stimulus package that she described as one of "the biggest and boldest countercyclical fiscal actions in American history."

Under Roosevelt, unemployment dipped from its 1932 peak but remained stubbornly high throughout the 1930s -- although today's economists cannot seem to agree on which set of numbers to use.

Some opt for statistics compiled by Wesleyan University economist Stanley Leberegott for the Bureau of Labor Statistics, which do not count many temporary jobs created by the New Deal. Others cite revised figures that count those jobs, producing a lower unemployment rate.

But even the revised numbers show unemployment never dipping below 9 percent in the 1930s. Not until the U.S. military buildup in 1940 did the rate tumble to a more acceptable 6 percent.

"The difference between these sets of numbers is the difference between terrible and awful," said Shlaes. "None would be acceptable to any politician today -- Democrat or Republican."

jtorry@dispatch.com