Mike, thank you for your very thoughtful comment. I certainly appreciate the nuance required for this topic, and it is difficult to achieve that in a short blog post. Your comment has made me consider how to express these details more effectively.
The hypothesis that rates of FGC should be very close to zero or one come from Mackie’s 1996 article (link in blog post) in which he proposes the social coordination norm theory. The two articles that I discuss in the post (Bellemare, Novak, and Steinmetz, 2015 and Efferson et al., 2015) delve much deeper into the tests of the hypothesis than I do in my job market paper.
I think that your overarching point is that people will deviate from the social norm even if there are strong social sanctions that accompany that deviation. While certainly practicing FGC and the lack of open homosexual behavior were enforced by social sanctions, I don’t think that homosexuality in the early post WWII period is a social coordination norm in the sense that Gerry Mackie proposes. It is not clear to me what homosexuals would be coordinating over. Acceptance of homosexuality is less about coordinating sexual preferences than FGC is about coordinating expectations on the marriage market. The key feature of a social coordination norm is that community members decide whether to participate in the norm based on how many other community members are participating in the practice. In the model there is somewhat of an implicit assumption that any family participating in the practice (in this case, FGC) will impose those social sanctions and families not practicing will not impose those sanctions. And I don’t think that holds for homosexuality.
I’m sure that there are other theoretical frameworks for analyzing the shift in opinions about homosexuality, but I don’t think that the social coordination norm would be a good fit for that analysis.