Is institutional sexism disadvantaging women in the workplace? New research suggests that something else could be to blame. The tax code’s design drives many married women to work fewer hours than they want to. Some women choose not to work at all, and bad policy is at least partly to blame.

The tax code and Social Security are littered with tax penalties for married couples. In many cases, a married couple’s secondary income earner pays more in taxes or receives fewer government transfers than if he or she was not married and filed taxes individually. And his or her marginal tax rate is at least as high as, and often greater than, his or her spouse’s.