As I wrote yesterday, momentum continues to build in Washington for a health-care reform that includes a provision for a government-sponsored program which would compete with private insurance companies. Greg Sargent highlights a telling new Rasmussen poll today, which shows that a large majority wants to open up health insurance companies to greater competition, with only 12% saying they think private insurers should continue to be exempt from anti-trust regulations. But lost in the argument over whether to include a public option and open up the health insurance industry to greater competition is another important battle over something known as "gender indexing."

Gender indexing—which is already illegal in 11 states—is the practice of taking into account gender when setting insurance premiums. As NPR reports today, although women in America are generally poorer than men, they typically pay higher health insurance premiums than men, at least up until the age of fifty. A recent National Women's Law Center study found that 25-year-old women can be charged as much as 84% more than 25-year-old men for health insurance—even for plans that don't cover maternity care. In addition, women are sometimes denied insurance for "pre-existing conditions" that include having had a Caesarean section—one woman was actually told she would have to be sterilized to be eligible for insurance. And other women report being denied coverage because they had been sexually assaulted.

Insurance companies defend gender indexing by saying it is no different from taking into account whether a person smokes or is obese. After all, why should they have to bear the costs of insuring people who are likely to have higher medical bills? But even if gender-indexing is based on a clear-eyed assessment of the costs of insuring women—rather than on what insurance companies think they can get away with—the analogy with smoking or obesity breaks down. There are good reasons why we might feel it is inappropriate for people to have to pay more for essential services like health care simply because of their race, their gender, their sexual orientation, or whether they have been a victim of a certain type of crime. Imagine how outraged people would be if health insurance companies announced that it was more expensive to insurance white males—even if it were true. As the Women's Law Center puts it in an online ad: "Being a woman is not a pre-existing condition."

Of course, ultimately it wouldn't be—and shouldn't be—private companies that bear whatever extra costs there are of insuring women. Men would probably have to pay relatively higher premiums to cover some of the cost of things like maternity care. But there are certain costs that are part of our common responsibility to bear as a society, as a matter of equity. When Sen. Jon Kyl (R-AZ) protested in a Senate hearing that as man he didn't need maternity benefits, Sen. Debbie Stabenow (D-MI) made this point perfectly when she responded, "Your mom probably did."