Photograph: Mark Reinstein/Corbis

After Nate Silver, the founder of the statistics blog FiveThirtyEight, correctly predicted the outcome of the 2012 Presidential election, Out magazine named him its Person of the Year. In an interview with Out, Silver spoke only briefly about being gay, but his comments on the topic attracted the most attention. “To my friends, I’m kind of sexually gay but ethnically straight,” Silver said.

Among those interested in Silver’s characterization was a sociologist named Amin Ghaziani, who has written a new book about America’s urban gay enclaves, “There Goes the Gayborhood?” In his book, Ghaziani portrays Silver—and his notion of being “ethnically straight”—as representative of a new gay sensibility, which Ghaziani, among others, calls “post-gay.” “Those who consider themselves post-gay profess that their sexual orientation does not form the core of how they define themselves,” Ghaziani writes, adding that “post-gays” spend just as much time with straight friends as with gay friends. “Actually, they generally do not even distinguish their friends by their sexual orientation.” (The "post-gay" concept is fraught, as it brings to mind the term “post-racial,” which refers to a time or place without racial prejudice and discrimination—a comparison Ghaziani seems to anticipate. “Post-gay does not mean post-discrimination,” he writes. Rather, Ghaziani uses the term primarily to refer to a period in which more gay men and women have the freedom to define themselves beyond their homosexuality.)

Ghaziani argues that the rise of post-gay culture has introduced a new turmoil in gay neighborhoods: more gay men and women are leaving for suburbs and smaller cities, and more straight people are moving in. According to the “index of dissimilarity,” which demographers use to measure the spatial segregation of minority groups, census data show that both male and female same-sex households became “less segregated and less spatially isolated across the United States from 2000 to 2010,” Ghaziani writes. Same-sex couples reported living in ninety-three per cent of all counties in the United States in 2010, prompting Ghaziani to conclude that, “gays, in other words, really are everywhere.” Ghaziani doesn’t think that this has wiped gayborhoods off the map—hence the question mark in his book’s title. But he documents a transformation that mimics that of earlier immigrant enclaves, triggered largely, he says, by the acceptance of gay men and women in the mainstream.

To document the country’s changing gayborhoods, Ghaziani combines demographic analysis with an examination of forty years of newspaper reporting on gay neighorboods. Ghaziani, who is gay, lived in Chicago’s Boystown for much of the aughts, and he uses Chicago as the primary case study. The decision to focus on Chicago, rather than, say, New York or San Francisco, has its limitations. Certain seminal events in gay history, like the AIDS crisis, which devastated a generation of gay men and radically transformed New York’s West Village, in particular, are only briefly mentioned. But we do learn more about a less-recognized, less-studied gay neighborhood.

Gay bars and clubs have existed since the late nineteenth century, but Ghaziani traces the rise of the gayborhood to the Second World War, when the military discharged thousands of men and women for being gay, and many looked for new homes in the cities that housed or were near their military bases, including San Francisco, Seattle, New York, and Miami. Gays and lesbians congregated mostly out of self-protection, Ghaziani explains, but gradually established rich social, business, and political networks that became draws in themselves, giving rise to such fixtures as the Castro in San Francisco, Dupont Circle in Washington, D.C., the South End in Boston, and Boystown in Chicago. These neighborhoods shared a few defining characteristics: known geographical boundaries, a concentration of gay residents who celebrated gay culture, and clusters of gay-friendly and gay-owned businesses.

Ghaziani argues that the current “de-gaying” of these iconic gayborhoods results more from gays and lesbians feeling safe outside of them than from straight people pushing gay people out. But he acknowledges that both gentrification and tourism have transformed gayborhoods. Gay couples tend to have fewer children than straight couples, and therefore have more discretionary income to invest in their neighborhoods, he says. After they revitalize an area, it often becomes a prime target for gentrification. (“We transform neighborhoods once undesirable into desirable neighborhoods that become too expensive,” the political scientist Kenneth Sherrill told the Village Voice in 2009. “They stop being the kind of funky, creative places we enjoy, and become sedate and snobby—and so we move on.”) Meanwhile, many cities are promoting their gay neighborhoods in the same way they market Little Italys and Chinatowns, attracting both straight and gay tourists. Chicago, one of the first to celebrate its gayborhood, installed large, rainbow-colored pylons along Halsted Street, the central artery of Boystown. In Philadelphia, officials added rainbow-flag decals to street signs and trademarked slogans like “Philadelphia—get your history straight and your nightlife gay.”

Ghaziani’s most interesting findings document what is happening beyond the gayborhood, in the new places to which gay men and women are relocating. He describes a process by which gay enclaves move across a city over time. In Chicago, for example, gays have moved systematically northward. After the Second World War, gays and lesbians first congregated in Old Town, a bohemian area, and then travelled up to New Town; in response to the Stonewall riots, in New York, in 1969, gay men and women in Chicago established Boystown, in Lakeview, which quickly became the city’s premier gay neighborhood; today, many gay men and women are leaving Boystown for Andersonville, farther north still.

These migrations can themselves stoke conflict. Ghaziani, among others, suggests that lesbians are sometimes the first to move into a new neighborhood—“canaries in the urban coal mine,” as the sociologist Sharon Zukin has put it—followed by gay men, who then dislocate the lesbians. Because women tend to have less purchasing power than men, lesbians are often the first to be pushed out. A woman in Chicago’s Andersonville neighborhood (also known as Girlstown) told Ghaziani that she was angrier about the gay men moving in than the straight people. “The straight couples are guests in our community,” she said. “The gay men are coming in to pillage. Imperialism is coming up from Boystown.”

The most dramatic demographic changes are occurring outside large cities. According to the 2010 American Community Survey, one per cent of all coupled households in the U.S. are gay, and, of these, twenty per cent report having kids. Consequently, many gay parents are moving from gayborhoods to nearby suburbs, while still others are congregating in conservative states like Mississippi and Idaho. “Many same-sex couples are raising children in states that have a legal environment that is at best not supportive and at worst openly hostile toward them and their families,” Ghaziani writes. Surprisingly, perhaps, the cities with the highest percentage of same-sex couples raising children include Salt Lake City and Bismarck, North Dakota.

It’s the sort of contradiction that Ghaziani argues lies at the heart of contemporary gay life. The fact that gay families live in both conservative and liberal areas across the country is evidence “that we are post-gay,” he writes. But the fact that gay families in conservative states tend to cluster in cities like Salt Lake suggests that many gay men and women still seek safety in numbers. Ghaziani predicts that, as gayborhoods thin out in large, coastal cities like New York and San Francisco, they will grow in smaller cities like Albuquerque and Richmond, Virginia, where acceptance is not yet as strong.

Ghaziani did not visit these emerging gay enclaves—“alas, there is only so much we can accomplish in one book,” he writes—but they seem already to have captured the imagination of some big-city residents. “Maybe the gay neighborhood in the Castro isn’t worth saving,” one Chicago lesbian, who once lived in Nebraska, told him. “But maybe the one in Arizona or Nebraska or New Mexico or Iowa or Idaho is absolutely worth cultivating.”