02/27/2013 01:25 pm ET Updated Feb 02, 2016

Separate but Equal Has Never Been Equal

Today our law firm signed an amicus brief filed with the U.S. Supreme Court in the case United States v. Windsor. This is the case in which the estate of a deceased spouse in a same-sex marriage was required to pay $363,000 in inheritance taxes that would not have been required if the couple had been straight instead of gay. The case challenges the validity of the Defense of Marriage Act (DOMA), which does not allow the federal government to recognize same-sex marriages.

There are dozens of good reasons to oppose DOMA. We signed the brief because we believe in marriage equality, and because we're employers. These two facts work together in this instance.

DOMA forces employers to treat lawfully married same-sex couples differently from lawfully married straight couples. For example, because of DOMA, employers must withhold more from the paychecks of married gay employees than from those of married straight employees. Married gay couples pay higher taxes than straight couples because the federal government does not recognize their marriages. This is the same problem that Edith Windsor, the surviving spouse in this Supreme Court case, faced when losing $363,000 to inheritance taxes.

Some companies choose to make up the difference to their gay employees because of the obvious inequity. Regardless of what various employers choose, the rule leads to unequal treatment and inevitably to morale problems.

In the brief we signed, we're simply asking for a rule that the federal government will not stop employers from treating all married couples, gay or straight, the same way.

Advocates of DOMA have often argued that state domestic-partnership laws allow gay couples to enjoy most of the benefits of marriage, but that marriage itself should be left only for straight couples. They have said that domestic partnership and marriage are different but equal and that there is therefore no need for gay couples to marry.

We learned during the civil rights movement that separate but equal is not equal, and we're learning it here again. DOMA's implications for legally married gay couples make it clear that separate is anything but equal when it comes to taxes. If treatment should be equal anywhere, it's in equal pay.

Equality is not selective; it's everywhere or nowhere. Separate but equal has never been equal.