Cameron's method had the virtue of simplicity, at least. He and two co-authors read through back numbers of various urban gay community papers, mostly of the giveaway sort that are laden with bar ads and personals. They counted up obituaries and news stories about deaths, noted the ages of the deceased, computed the average, and published the resulting numbers as estimates of gay life expectancy.
What do vital-statistics buffs think of this technique? Nick Eberstadt at the American Enterprise Institute sums up the reactions of several of his fellow demographers: "The method as you describe it is just ridiculous." But you don't have to be a trained statistician to spot the fallacy at its heart, which is, to quote Centers for Disease Control and Prevention statistician John Karon, that "you're only getting the ages of those who die." Gay men of the same generation destined to live to old age, even if more numerous, won't turn up in the sample.