Rational Gay Union Policy

I'm not attempting to steal JurisNaturalist's thunder, but our recent discussion of the rationality of gay union is even more important to post because we're both fairly conservative Christian men.

JN sent me an e-mail this morning about a possible paper topic. A general outline of our discussion (he might contest it was one-sided pontificating) is below.

Assumptions:

1. Heterosexual unions (hereafter referred to as "marriages") are good for society. They promote procreation, family values, sexual and mental health, and general happiness.
2. Heterosexual couples choose to enter into marriage for these reasons, and according to individual sets of tastes and preferences (often, individuals are said to display a "vector" of preferences, tradition being one common example).
3. Marriage is a private contract and subject to analogs of common contract law. Divorces, alimony, custody and more have analogs in breech of contract, reparations, and property ownership, respectively (forgive the coldness).
4. Individuals enter into contracts only when it is beneficial to both parties.
5. It has not been widely shown by credible sources that homosexual unions (hereafter referred to as "gay unions") are not afforded the same quality of life improvements set forth in step 1.
   
6. It follows that all couples, regardless of sexuality, benefit from union (steps 1 and 4 with 5).
7. As long as individuals benefit, society's welfare increases.
8. It is in the best interest of governments to sanction unions for all couples.

Caveats:

1. Some members of society may receive disutility from the existence of gay unions. One might imagine an extreme conservative Christian to be extremely irked by his state's passage of such a law. In this case, social welfare decreases.
2. Some members of the gay community receive disutility from the ban or non-recognition of gay unions. One might imagine an extreme leftist progressive becoming irate over a state ban of gay marriage. In this case, social welfare also decreases.

We are left with no decision. Either banning or allowing gay union will decrease social welfare. We much measure the total welfare effect of each and compare three worlds:

1. Where gay union is allowed
2. Where gay union is banned
3. Where those receiving disutility from the permission of gay union do not exist

In the first two worlds, both containing the individual that receive disutility from permission, social welfare is not optimal. When that common factor is removed, in world 3, social welfare is optimized based on the above assumptions (thought process).

We see, then, that the market for gay union has a positive externality in that it increases total social welfare, but costs of offending idealogues are included in any individual policy decision. Following general theory of market failures and government intervention from any basic resource economics course, one sees that gay unions are underprovided. This is much in the same way that education is thought to be underprovided in Externalities in a Nutshell; however, in that article, higher than normal costs are borne by buyers but in gay unions, these costs are borne by other individuals.

It occurs to me that, by my last statement, this means the market for gay unions contains a negative externality, not a positive one. This means that the market over-provides the number of unions. However, I believe this discrepancy lies in whom one place initial rights (see Property Law or Google for some more information on "initial allocation". If anyone can find a hole in my logic, please leave a comment. If a negative externality is actually the case, the following analysis is perfectly incorrect.

The common solution, then, is that government intervene to create an environment conducive to more gay unions, either silencing or removal of the offended, or in some other way encouraging couples to enter this contract. If this means subsidizing the union, then I see potential laws being similar to current marriage laws, including tax breaks for the union, for raising children, etc.

It seems more likely, however, that the first step be allowing the unions to take place at all.