Fraction of couples that are same-sex:

Clayton Cramer complains about “Credulousness In the Blogosphere”: People are citing statistics that, for instance, “In California, 1.4 percent of the coupled households are occupied by same-sex partners,” but he doesn’t buy it:

Contrary to [Virginia] Postrel’s claim that 1.4 percent of Californian households are gay couples, the actual number–92,138 same-sex couples in California, multiplying by two to get the number of people, and dividing by California’s population–comes to about 0.55% of the population. I am very skeptical of the rest of the statistics that Postrel is quoting. I suspect that someone is looking at same-sex households, and assuming that these are all gay couples. They may well be roommates.

     Well, Cramer is right to point out that the story Postrel links to as the source of her statistics doesn’t contain them — sounds like a wrong link to me; the right one seems to be this one, which I found simply by doing a google search for the quote that Postrel gives (and it is, indeed, an AP story). But just a bit of online searching (I searched for “92,138 california” on the Census Web site) found me something even better — the relevant Census document. Some observations:

1. The Census apparently does not assume that all same-sex households are gay couples. “These unmarried-partner households were self-identified on the census form as being maintained by people who were sharing living quarters and who also had a close personal relationship with each other. . . . [footnote:] In contrast, people who were sharing the same living quarters but were doing so just to share living
   expenses were offered the opportunity to identify themselves as roommates or housemates. [end footnote]” It’s conceivable that the data erroneously includes siblings, who have a close personal relationship; I suspect that the Census wouldn’t have been careful enough to distinguish roomates and housemates, but not have distinguished siblings or other blood relatives, but if I’m mistaken please let me know. [UPDATE: D’oh! Reader Eyal Barnea points out that the questionnaire is right there on the page, in a nice big inset that I somehow unaccountably skipped over. It definitely does distinguish siblings and other relatives from partners, so my suspicion that the Census is indeed focusing on couples and not just relatives or roommates is correct. “Unmarried partners” thus refers to people who are really identified by the respondents as partners.]
2. The article that Cramer quotes says, “To date, the Census Bureau has reported that there are 479,107 same-sex couples sharing a household. This number will rise when data from all 50 states is released.” Apparently this has happened — the national estimate is now nearly 600,000, out of nearly 60 million coupled households, or about 1%.
3. The California statistics are as Postrel reports them: 1.4% of all coupled households are same-sex partner households, 92,138 same-sex households out of a bit over 6.5 million coupled households.
4. Cramer’s statement “Contrary to [Virginia] Postrel’s claim that 1.4 percent of Californian households are gay couples, the actual number–92,138 same-sex couples in California, multiplying by two to get the number of people, and dividing by California’s population–comes to about 0.55% of the population” (A) misstates Postrel’s claim, and (B) misestimates the California data. First, Postrel didn’t say that 1.4 percent of Californian households are gay couples; she said (quoting her source) that 1.4 percent of coupled households are gay couples. Cramer quoted this claim accurately earlier in his post but then misinterpreted it in his criticism. Second, Cramer’s denominator, which is essentially the California population divided by 2, is neither the number of coupled households in California nor even the number of households, unless California is occupied by 34 million people neatly divided into 17 million couples. The total number of California households, according to the household, is 11.5 million; the total number of coupled households is a bit over 6.5 million.

Virginia Postrel is almost entirely right in her statistics (at least assuming the Census data is good); her only error is in her link. Clayton Cramer’s criticism is misplaced — and a couple of easy online searches would have given him the raw data that I describe above.

UPDATE: Clayton Cramer has acknowledged the error, and I much appreciate that. He then goes on, though, to argue:

This would suggest, however, that one of the arguments for gay marriage–the supposed stability that legal marriage would provide–isn’t much of an argument. Homosexuals are about 3% or so of the population–and about 1.4% of couples. Unsurprisingly, half of these same-sex couples are female, even though homosexual men outnumber lesbians by perhaps three times.

I’m not sure I quite get this. Cramer correctly points out that some homosexuals are in couples even without marriage as an option. But the claim isn’t “Without homosexual marriage, homosexuals can never form couples.” Rather, it’s that homosexual marriage makes it harder to form long-term couples. After all, even without heterosexual marriage, lots of men and women would live together as couples; but the assumption is that heterosexual marriage helps men and women do that, and also helps those couples last longer (perhaps even for the duration of the members’ lives). That is also the argument made in favor of homosexual marriage. I just don’t see how the data that Cramer now correctly cites undermines that argument.