An economist delving into why Americans pay more than Canadians for health care has discovered one important reason: U.S. doctors charge twice as much for doing less.

Despite their bigger fees, U.S. doctors earn only about one-third more than their Canadian counterparts, said the study. This is largely because they see fewer patients and have higher overhead for such things as fancier offices.Health care for Americans costs an average of $1,780 per year, while for Canadians it costs $1,286, according to the study by economist Victor R. Fuchs of Stanford University.

Overall, physician fees are 2.4 times higher in the United States, he said. Differences in hospital bills and other expenses also contribute to the lower cost of medical care in Canada.

However, Canadian doctors do not save money by skimping on patient care, Fuchs said. In fact, he found that they provide about 25 percent more services to their patients.

Canada provides complete, fully paid health coverage for all citizens. In the United States, one in seven people has no health insurance, and even those with coverage typically have to pay at least part of the bill.

"If physician fees in the United States were the same as in Canada, by how much would total health-care expenditures be reduced?" said Fuchs. "If the fees were cut in half and lowered to the Canadian level, total expenditures would be reduced by about 10 percent."

His calculations, which converted Canadian figures into U.S. dollars, were based on 1985 data and published in the New England Journal of Medicine.

Among the findings:

- U.S. fees for surgery and other high-tech services such as X-rays and anesthesia were more than three times higher.

- On a per capita basis, Canada had more doctors but fewer specialists.

- U.S. doctors are paid five times more than Canadians for visiting patients in the hospital.