Every day, 10 hours a day, David Wile hoists hundreds of boxes of alternators and windshield wipers onto the assembly line at General Motors Corp.'s Astro and Safari van plant.

Last week, if the 48-year-old autoworker sat down for a minute, one of his pals down the line shouted at him: "Hey, lazy American worker! Get up!"

Mr. Wile and his friends at the Broening Highway plant were joking about comments by Yoshio Sakurauchi, speaker of Japan's lower house of parliament, who last week blamed the U.S. trade deficit on American workers who "won't work hard."

Mr. Sakurauchi has stirred up a firestorm of outrage among workers like Mr. Wile, who considered the statement "a terrible slap in the face."

But behind last week's anger lingered a bit of soul-searching. In factories and offices last week, people wondered: Was Mr. Sakurauchi right? Are American products losing market share because the American work force is getting lazy?

The answer, it turns out, is, "Not exactly." Americans work plenty hard, according to a variety of international comparisons.

But there is disturbing evidence the United States may be suffering in the international marketplace because domestic workers and managers aren't working smart enough.

"There is a grain of truth to what this guy [Mr. Sakurauchi] said," conceded Martin Bailey, a University of Maryland economist who specializes in productivity research.

After all, Mr. Sakurauchi's comments weren't all that different from criticism leveled by hundreds of U.S. executives, managers and economists in the past.

Students' test scores are declining. The U.S. trade deficit with Japan has become massive.

And since 1982, U.S. improvements in manufacturing productivity has lagged behind such nations as Belgium, Italy, Japan and Great Britain.

Roseanne Helgemo, who runs a sandwich shop on Philadelphia Road in Baltimore County, said that she has a good crew of workers now, but that it took her nearly two years of weeding-out to find them.

"Sometimes I'd get on a roll and fire three workers a month" for just standing around, said the manager of Michael's Overstuffed Subs. "A lot of people are really lazy," she said.

But the picture isn't as dim as most people believe.

There is growing statistical and anecdotal evidence that Americans are working harder than ever, and harder than everyone in the industrialized world -- except, perhaps, for Japanese men.

In fact, as a group, Americans are still the most productive workers in the industrialized world, according to Department of Labor analyses.

Americans also spend more time at work than almost any other group of people in the industrialized world. Europeans, for example, get twice as much vacation time, averaging five weeks a year.

And unlike workers in every other industrialized nation, Americans are working longer every year, said Harvard economist Juliet Schor in a controversial new book, "The Overworked American."

U.S. manufacturing employees work 320 hours (the equivalent of two months) more than their counterparts in West Germany or France each year, she wrote.

Statistics for white-collar workers are hard to come by, but there is growing evidence that they, too, are intensifying their efforts.

Kirby Farrell, who runs the telecommunications division of a Washington-area engineering firm, said he remembers when he had so much free time he could watch Johnny Carson and David Letterman at night.

Now he puts in 65 hours a week at ECI Systems and Engineering, "and if I got home at 6 p.m., I'd microwave dinner and be done by 6:20. I don't know what I'd do."

He isn't alone. Nicholas Burns, maitre d' at the Brass Elephant restaurant, a popular spot for Baltimore executives, said he's watched the demise of the two-martini lunch.

"Businessmen would come in, have two or three drinks, then wine with lunch, and they'd be here for two, 2 1/2 hours" in the mid-1980s, he said.

Now, customers order quick lunches and iced tea. They want to be back in their offices in an hour, he said.

Despite Americans' buckling down, Japanese men still spend more time at their full-time jobs than any other group. But they are able to do so because their wives are usually full-time homemakers, Ms. Schor noted.

Counting both home and paid work, American men and women work longer hours than do their Japanese counterparts, she found.

There are signs, in fact, that it is the Japanese who are slacking off, said University of Michigan researcher Frank Stafford. The Japanese are spending less time at work each year.

Another potential sign of Japanese loafing: They watch more television than Americans watch. During the 1980s, Japanese men watched an average of 17.3 hours of television a week. American men averaged 12.4 hours a week. "And television watching is the most useless activity we do," Mr. Stafford said.

Though reassuring, such international comparisons don't explain away the United States' stagnating productivity and its trouble in the international marketplace. And as the domestic economy worsens, groups attempt to affix blame.

Barry Rideout, a worker at the local Locke Insulator plant, said he knows neither he nor his fellow workers can be accused of loafing.

Mr. Rideout worked for the insulation plant when it was owned by General Electric Co. and now that it is owned by a Japanese firm.

Both sets of managers paid most of the workers by piecework, "so you really don't have time to be lazy," he said.

The biggest difference: Under GE, the local plant seemed "top heavy in management," Mr. Rideout said. "They've since scaled down."

Several prominent economists agree with Mr. Rideout.

A Harvard Business School study found that Japanese automakers were 32 percent faster at developing and engineering new models than were their U.S. competitors.

And a Massachusetts Institute of Technology study of the international automotive industry concluded that the problem wasn't American workers. It was American management.

The MIT study found that while U.S. car plants run by U.S. companies are less productive and less quality-conscious than are Japanese plants, Japanese-run U.S. plants were among the most competitive factories in the world.

Workers at the California GM plant taken over by Toyota doubled their productivity and slashed their defect rate, said James Womack, one of the authors of the MIT study.

U.S. managers have started to close the gap, but now they are losing an image war, Mr. Womack said. The Japanese have convinced customers to pay more for their cars, and are taking their extra profits and plowing them back into their businesses.

"They don't pay much in the way of dividends," Mr. Womack explained. U.S. companies tend to distribute profits in dividends and investments. U.S. companies "start going out buying executive-jet companies and savings and loans. Is it any wonder the Japanese are winning?" he asked.

And even if Japanese workers do work harder, many workers and economists wonder if we should care.

"Maybe we are putting work in its proper perspective," said Gary Burtless, an economist at the Brookings Institution.

Mr. Wile wonders the same thing. "I get the feeling the Japanese worker lives to work. Whereas we work to live," he said.