The report, issued by the International Labor Organization, found that Americans added nearly a full week to their work year during the 1990's, climbing to 1,979 hours on average last year, up 36 hours from 1990. That means Americans who are employed are putting in nearly 49 1/2 weeks a year on the job.

Americans work 137 hours, or about three and one-half weeks, more a year than Japanese workers, 260 hours (about six and one-half weeks) more a year than British workers and 499 hours (about 12 1/2 weeks) more a year than German workers, the report said. The Japanese had long been at the top for the number of hours worked, but in the mid-1990's the United States surpassed Japan, and since then it has pulled farther ahead.

"It's unique to Americans that they continue to increase their working hours, while hours are declining in other industrialized nations," said Lawrence Jeff Johnson, the economist who oversaw the labor organization's report. "It has a lot to do with the American psyche, with American culture. American workers are eager to make the best impression, to put in the most hours."

Many economists say the numbers demonstrate that the American economic boom of the 1990's provided plenty of work for tens of millions of Americans. In contrast, the economies of Europe and Japan grew far more slowly, if at all, causing many companies to cut back on the length of the workweek.

Patrick Cleary, senior vice president for human resources policy at the National Association of Manufacturers, said, "Clearly, for most of these years the increase in hours tracks outstanding economic performance in the United States, which translates into more income for all those workers, so we don't see this necessarily as bad news at all."

Among the reasons for the large differences between the United States and other countries are that Europeans typically take four to six weeks of vacation each year while Americans take two to three weeks. And while American employers kept adding overtime during the 1990's, in France the government reduced the official workweek to 35 hours.

Juliet Schor, a sociology professor at Boston College and the author of "The Overworked American," said one reason for the nation's longer average work year was that American workers seemed to be increasingly squeezed during booms and busts alike.

"All the direction seems to be for longer hours," Ms. Schor said. "In expansions, companies keep giving more work to their workers, and in recessions, there will be downsizing and fewer people working, but the workers who remain have to work longer hours to retain their jobs."

Many economists say the number of hours that Americans work each year may begin to level off now that many automakers and other manufacturers have reduced the amount of overtime assigned due to the economic slowdown.

Economists give many reasons for the increase in the number of hours that Americans work. Mothers with young children tend to work sooner and for more hours per week than young mothers did a decade or two ago. More Americans are salaried professionals, like investment bankers and lawyers, who often work 60 or more hours per week. In addition, many low-wage workers have two or three jobs to make ends meet.

In the best news for the United States, the report ranked the country No. 1 in the world in productivity per worker. It said that last year, productivity per American worker in constant 1990 dollars was $54,870, about $1,500 more than Belgium, the No. 2 nation. The report found that productivity per worker in the United States was $10,000 higher than in Canada last year, and $14,000 higher than in Japan.

But partly because of the comparatively high number of hours that Americans work, the report found that France and Belgium edged out the United States in productivity per hour. In France, which ranked first, workers produced $33.71 of value added per hour on average, compared with $32.98 in Belgium and $32.84 in the United States.

Ellen Galinsky, president of the Families and Work Institute, a research group in New York, said the large number of hours that Americans work could result in burned-out workers with lower productivity.

"Our overall productivity is high because we work more hours," Ms. Galinsky said. "But our research shows there is a possible point of diminishing returns."

Copyright 2001 The New York Times Company

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