After a decade of nearly flat federal funding for biomedical research, inflation has eroded more than a fifth of the buying power for scientists studying genomics, neurology, cancer, heart disease, diabetes, HIV/AIDS and countless other aspects of human health.

Henry R. Bourne, an experimental biologist and professor emeritus at the University of California, San Francisco, argues in a recent Internet publication and elsewhere that the problem existed long before the National Institutes of Health (NIH) budget flatlined in 2003, however. He says the culprit is three previous decades in which NIH’s budget increased an average of 10 percent a year.

Bright young minds followed the money, creating an unsustainable glut of scientists, Bourne said in a recent interview.

With so many people competing for grants, NIH had to restrict the percentage of requests that got funded. But the system has become irrational because the reviewers who score the proposals can’t reliably distinguish between great ones and very good ones. As a result, many great ones go unfunded.

“Once you get to where money is really limited, what competition does is really screw people,” Bourne said.

He likened the problem to the “tragedy of the commons,” an economics reference to overgrazed grasslands in England in the 1800s. If unchecked, the theory goes, individuals will take what they can get from shared resources, leading to overuse and possibly irreversible damage. “We’re all doing ourselves in,” Bourne said. “It’s very much like global warming.”

He said NIH funding also has led to too many new academic research buildings at the expense of the people who fill them: legions of postdoctoral fellows working for too little money.

Bourne said that when money gets tight, it flows to the sure thing, or to ongoing projects led by famous scientists.

“Basic science is not keeping up with the needs of society,” he said. “It’s not going to be fixed by another large infusion of money … It’s a cultural thing that needs to be changed.”