In 1989, Denmark began allowing homosexual couples to form "registered partnerships," which gives a couple most of the legal rights of married persons; the other Scandinavian countries followed suit. In 2001 the Netherlands began allowing homosexual couples to marry. Spain followed, despite the fierce opposition of the Catholic Church. Canada too, and it is plain that most North Atlantic nations will soon recognize gay marriage. In the United States, Massachusetts and California, by virtue of state court constitutional rulings, now allow gay marriage. Several other states recognize "civil unions" or "domestic partnerships," the equivalent of Denmark's registered partnerships. (All these laws, except the Scandinavian ones, are recent, and there have been few studies of their effects.) The federal Defense of Marriage Act (1996), however, not only denies the federal benefits of marriage to gay marriages, but also empowers states to refuse to recognize such marriages, and a majority of states have enacted laws (usually as part of the state's constitution) refusing to recognize such marriages.
The gay-marriage movement raises a number of interesting questions, which I approach from an economic perspective: why do homosexuals want to marry? What are the consequences of gay marriage likely to be? Why is there opposition to gay marriage?
All sentimental and religious considerations to one side, marriage is a source of benefits. One, which is a genuine social benefit, is a saving of transaction costs. If you want to leave money to someone to whom you are not married, you will need a will; but if you are married, upon your death your spouse (if you have no will) will automatically receive a share of your estate. Nor do you have to have a contract specifying the financial or other consequences of an abandonment or other dissolution of the relationship; the law of divorce supplies the necessary machinery. In other words, the law provides a kind of standard contract that enables the costs of negotiating and drafting a private contract to be avoided. In this respect it is very much like partnership law, so that the term "domestic partnership" to describe a marriage-like law for homosexuals is apt.
There are also private benefits (in the sense that there does not seem to be an efficiency justification for them), such as survivors' social security benefits and rights under the Family and Medical Leave Act, but most of these benefits (offset, but for most couples not fully, by the "marriage tax"--the higher incomes taxes paid by a couple each of whom has a good income than they would have to pay if they were not married) are federal, and the Defense of Marriage Act denies federal marriage benefits to the parties to gay marriage. There are also, however, state-law evidentiary privileges that enable one to prevent his or her spouse (or sometimes even ex-spouse) to testify against one in a criminal case.
Employers often provide health and other benefits to the spouses of their employees as well as to the employees themselves, but there is nothing to prevent employers from offering those benefits to a same-sex partner of the employee, whether or not married.
Given the Defense of Marriage Act (and no-fault divorce, which enables each spouse to dissolve the marriage unilaterally), the net benefits of gay marriage to homosexuals are small, and indeed no greater than those conferred by domestic-partnership laws. Nevertheless, most homosexuals are very strong supporters of gay marriage even on the assumption that the Defense of Marriage Act will not be repealed and even though it appears that relatively few homosexuals have taken advantage of the Massachusetts law, though this may be because of its newness; it was created by the state's highest court by an interpretation of the state's constitution in 2004, and there was initial uncertainty whether it would stand, or be nullified by constitutional amendment. But probably the main reason for homosexuals' support of gay marriage is simply their desire to be treated equally with heterosexuals, which probably is also the principal reason for homosexuals' opposition to the armed forces' discrimination against them, rather than a great desire for either marriage or military service.
What are likely to be the consequences of gay marriage? If few homosexual couples take advantage of the right to undertake such a marriage, the consequences, at least in the short run, will be slight, especially since the right will be recognized in only a few states for the foreseeable future. But even if all states recognized gay marriage and the Defense of Marriage Act were repealed, the consequences would be small simply because the homosexual population is small and many homosexual couples will not bother to marry; many heterosexual couples nowadays do not bother to marry, especially if they don‚Äôt plan to have children, and a higher percentage of heterosexual than homosexual couples do not plan to have children. The much-bandied-about figure that 10 percent of the population is homosexual is false; it is based on a misinterpretation of Kinsey's data. The true figure is about 2 to 3 percent for men and 1 percent for women.
My qualification "in the short run" was intended to leave open the question whether widespread recognition of gay marriage, and thus the legitimating of homosexual relationships, might either increase the number of homosexuals or undermine heterosexual marriage. I do not think either consequences is likely. Sexual preference seems pretty clearly to be genetic or otherwise innate rather than chosen on the basis of social attitudes toward particular sexual practices. Despite greatly increased tolerance of homosexual behavior in many countries (including the United States) in recent decades, there is no evidence that I am aware of that the number of people who prefer homosexual to heterosexual sex has grown. Homosexuals are more open about their sexual identity and this creates an impression that there is more homosexuality than there used to be--and there may indeed be more homosexual behavior. But the preference appears to be unchanged. So parents probably need not worry that recognizing gay marriage will increase the likelihood of their child's turning out to be homosexual.
Although some of the opposition to gay marriage is religiously motivated, I believe the main opposition comes from the feeling of many (heterosexually) married people that allowing gay marriage degrades or depreciates the concept of marriage, much as if polygamous marriage were permitted or people were permitted to marry their dogs or their automobiles. Apart from the weight that widespread public opinion is entitled to be given in a democratic society, there is the danger that if people respect the institution of marriage less, the marriage rate, already low, will fall still lower, with adverse social consequences. Again, the danger seems small. The people who worry about the effect of gay marriage on the institution of marriage are those most committed to the institution, and they are unlikely to desert it. And if they did? If what marriage mainly is is simply a standard contract, it is not obvious that its decline, and replacement by private contracts (in other words, the privatization of marriage), would have serious social consequences, given the ease with which under modern law marriages can be dissolved by either party.
Marriage retains and will probably long retain tremendous symbolic significance in our society as a symbol of love and commitment (that is why cheating on a spouse attracts greater opprobrium than cheating on a person with whom one has a long-term, but not marital, sexual relationship), and it is likely to retain that significance even as gay marriage becomes more widespread, as it seems bound to do.