An oversupply of doctors that is widely predicted for the turn of the century will not materialize, and there could be a shortage instead, two reports predict.

The reports contradict an often-repeated prophesy that the nation will have tens of thousands too many physicians by the year 2000 and so should train fewer doctors."I see no basis for cutting back on the number of new physicians," said Dr. William B. Schwartz of Tufts Medical School. "I think we are likely to be in rough balance and could have even a modest shortage of physicians."

In general, Schwartz's report and another by Dr. Ernest P. Schloss of the University of Arizona argue that the earlier predictions overstated the supply of doctors and underestimated demand for their services.

Schwartz said the predictions of too many doctors already have had an impact.

"Many college students are looking on medicine as an unpromising career, in part because they are being told that there is going to be a huge physician surplus," he said in an interview. "That is undoubtedly one of the factors that has led to a sharp reduction in the number of applications to medical school," which have fallen 15 per cent since 1981.

Schwartz' report, the more detailed of the two, projects that 592,000 physicians will be needed by the turn of the century, and 585,000 will be available.

Both papers were published in the New England Journal of Medicine.

One of the most widely quoted of the earlier projections was a 1980 report by the Department of Health and Human Service's Graduate Medical Education National Advisory Committee. It predicted that in 2000, there will be 144,700 too many physicians.

However, Schwartz said that and other predictions greatly overstated the supply of doctors. The biggest mistake was assuming that all the nation's doctors will be treating patients. Instead, Schwartz said, about 93,000 of them will be administrators, teachers and researchers.

Another miscalculation, he said, was failing to take into consideration the impact of the growing proportion of female doctors, who, studies show, work about 10 percent fewer hours than their male counterparts.

The earlier predictions also did not foresee a movement to require resident physicians to work shorter hours in big teaching hospitals.

Schwartz said the earlier predictions also made a mistake by assuming that the demand for physicians will remain constant. Instead, he said, demand has been growing at a rate of over 1 percent per year for several decades. The availability of new kinds of care, such as exotic imaging machines, transplants and genetic analysis, may speed up the demand for more doctors.

Other factors that could increase demand, he said, include the increasing age of the population, wider medical insurance coverage and the AIDS epidemic.

Dr. Robert G. Petersdorf, president of the Association of American Medical Colleges, has warned for several years of an impending doctor glut. He said Schwartz's study underestimates the supply of doctors and overprojects the demand for them.

"I agree with the authors that the presumed projected oversupply should not act as a deterrent to choosing medicine as a career," Petersdorf said. "At the same time, I am not prepared to state that an oversupply does not exist. The support for such an assertion is based on assumption and not on fact."