Novartis, the company that makes the leukemia drug Gleevec, keeps raising the drug’s price, even though the drug has already delivered billions in profit to the company. In 2001 Novartis charged $4,540, in 2014 dollars, for a month of treatment; now it charges $8,488. In its pricing, Novartis is just keeping up with other companies as they charge more and more for their drugs. They know we can’t say no.

But what if we didn’t require insurance companies to cover all drugs? We can see the answer in Europe. Many European countries say no to a handful of drugs each year, usually those that are both pretty ineffective and highly costly. Because they can say no, yes is not a guarantee. So companies have to offer their drugs at prices that make them attractive to these health care systems. A recent survey of cancer drug policies revealed you don’t have to say no very often to get discounts for saying yes. Of the 29 major cancer drugs included in the study that are available in the United States, an estimated 97 percent and 86 percent are also available in Germany and France, respectively.

As a consequence of the stand taken by those countries, prices in Europe for prescription drugs are 50 percent below what we pay, according to a McKinsey study from 2008. Gleevec costs $4,500 per month in Germany today, and $3,300 per month in France, less than what Americans paid in 2001.

Saying no, or even the threat, works to lower prices in the United States, too. But it’s rare. In 2012, my hospital said we wouldn’t give the colon cancer drug Zaltrap to our patients because it cost twice as much as another drug (Genentech’s Avastin) that was just as good. When we refused to use it, the company realized that other cancer hospitals and doctors might follow, and halved its price nationwide.

More recently, Express Scripts, a company that manages pharmacy benefits, showed that approval was no guarantee. It was therefore able to play two makers of treatments for hepatitis C off against each other. Express Scripts said yes to AbbVie’s Viekira Pak (for the most common subtype, genotype 1 disease), and said no to Gilead’s Sovaldi and Harvoni. Another pharmacy benefit program, CVS Caremark, played it the other way, closing out AbbVie and choosing Gilead.