Sure, we also have female party promotion groups like Traxx Girls that host frequent events, and other bars have “ladies night” or just evenings that are known to be popular with lesbians. But when it comes to sustaining the revenue needed to keep an actual “place of our own” open (rent, utilities, staff, etc.), we just can’t seem to do it.

Critics can certainly point to reasons they think particular women’s bars have failed to survive in Atlanta. A bar can always offer more of this, less of that. One key to My Sister’s Room’s longevity may lie in its three different locations — first at the Midtown Promenade shopping center, then quirky Decatur, now in hip East Atlanta Village — as moves forced the bar to renovate and revise, perhaps keeping it fresher for patrons.

But I have to think there is something more to the lack of lesbian nightlife than this. Regardless of specific bars, it’s hard to remember a time when Atlanta supported more than a couple of women’s bars.

Back in the mid-‘90s, we had the Otherside and Revolution, which briefly overlapped with My Sister’s Room. Longtime lesbian residents of the city can recall fond memories of bars like Deanna’s One Mo Time and the Sports Page. But never, never has the scale of lesbian nightlife in the city remotely approached the tally of bars for gay men.

The same appears to be true in other major cities. Even if they have more lesbian bars than Atlanta, they still have far fewer lesbian bars than gay bars.

Why? The answer likely lies in a myriad of cultural, social and economic factors. Here are a few theories.

• What if there are fewer lesbians than gay men, so we don’t need as many bars?

The Census doesn’t count lesbians and gay men, although same-sex couples can be counted (by looking at the sex of the partners who mark that they live with a “spouse” or “unmarried” partner). The 2010 Census counted 15,271 female couples and 14,573 male couples in Georgia. Nationally, 332,887 female couples and 313,587 male couples were tallied.

Even if you assume that lesbians may be more likely to be in couples than gay men, meaning there are more single gay men to add to the totals than single lesbians, it’s unlikely that gay men outnumber lesbians by the same ratio that gay bars currently outnumber lesbian bars in Atlanta, which is roughly 24 to 1.

• Lesbians are more likely to be in couples, and lesbian couples go out less than gay male couples.

We’ve all heard the jokes: “What do lesbians do on a second date?” “Rent a U-Haul.” “What do gay men do on a second date?” “What’s that?”

Not only might more lesbians be coupled than gay men, but gay male couples seem to still go out more than their female counterparts. Years ago, the lesbian owner of the Otherside Lounge told me about the problem she felt her bar had in attracting consistent female patrons: Essentially, she said she would see single women come to the bar pretty regularly, then they would meet someone and disappear, and not come back for months or years until they were single and looking again.

While gay men who are coupled may not go out as often as gay single men, it still seems anecdotally that more gay couples go out than lesbian couples. Add that more lesbian couples than gay couples are raising kids, either planned together or from previous heterosexual relationships, and the result may be even less time for nightlife.

‎As PFLAG Atlanta quipped on Facebook today, responding to a ProjectQAtlanta post about a lesbian parenting study, “The long-running mystery of why there’s always more bars for gay guys than lesbians is now solved: The gays party while the lesbians couple up to stay home and raise happy teens.”

• Lesbians have less disposable income.

Going out is expensive. Gender disparities mean that women still earn less on average than men, meaning lesbians may have less money to party with than gay men.

• Bars don’t play the same role for lesbians in coming out and socializing that they do for gay men.

Many gay men, especially from older generations, recall their first visit to a gay bar as the first place they were able to be out and feel accepted. That’s true of some lesbians as well, but lesbians also often recount sports teams, summer camps, concerts by female musicians and other female-centered spaces as the first place they met or felt comfortable with other lesbians, which then became the center of their social network.

Which of these theories do you think might play a role, and which are just plain bunk? What other reasons do you think might account for the vast difference in lesbian and gay male nightlife?