Early-stage cancer drugs that could extend life by years are arguably more valuable to patients than drugs that can add only a few months to the end of a battle with cancer. But pharmaceutical firms “underinvest” in research for these long-term cancer drugs, according to a paper coauthored by Heidi Williams, an assistant professor of economics who received a MacArthur Foundation “genius” grant in September.

Partly because drugs for late-stage cancer do not extend people’s lives for long, those clinical trials wrap up more quickly and cost less than those for early-stage drugs. And with shorter trials, the drugs hit the marketplace faster, giving pharmaceutical companies more time to sell them under exclusive patents.

“There is a pattern where we get more investment in drugs whose clinical trials take a short time to complete, and less investment in drugs that take a longer time to complete,” says Williams, who coauthored the paper in the American Economic Review with Benjamin Roin, an assistant professor at the MIT Sloan School of Management, and Eric Budish of the University of Chicago.

The social cost is significant: the researchers estimate that inadequate investment in longer-term drugs resulted in a loss of 890,000 life-years among people who were diagnosed with cancer in 2003 alone.

The finding “doesn’t mean that the private firms are doing anything wrong,” Williams adds. However, she observes, “the public sector is more willing to invest in these long-term projects than is the private sector.”

To conduct the study, the researchers analyzed four decades’ worth of data involving more than 200 subcategories of cancer and drawn from many sources, including the National Cancer Institute and the Food and Drug Administration. When they analyzed leukemia and lymphoma research, they discovered that those trials often don’t use mortality to establish effectiveness, relying instead on “surrogate endpoints”—biomarkers standing as proxies for eventual outcomes, which allow for shorter trials. For these cancer types, there were more trials and more money was poured into research, other things being equal. “When you have good surrogate endpoints, you see a dramatic increase in R&D investment, which means lives saved,” Roin says.

The researchers suggest three policy adjustments that might produce more research on long-term cancer treatments. The first is to study whether surrogate endpoints can be used more widely. A second is more public funding for cancer treatments that require longer clinical trials. (All six preventive cancer drugs in existence used public funding or surrogate endpoints in their trials.) A third is to change the monopoly term for new drugs so that it starts when the drug hits the market, not from the moment, typically during early research, when the patent is filed.