Lap Dancers, Menstrual Cycles, and Earnings

Yes, there is a study even of that. I saw it in today's announcement of the annual ig-Noble awards - work that is just plain funny because it's actually real scientific research. In the economics category, Geoffrey Miller, Joshua Tybur, and Brent Joran (all from the University of New Mexico) were recognized "for discovering that a professional lap dancer's ovulatory cycle affects her tip earnings." The paper was published in Evolution and Human Behavior, November 2007, and is entitled "Ovulatory Cycle Effects on Tip Earnings by Lap Dancers: Economic Evidence for Human Estrus?". Here's the abstract.

To see whether estrus was really “lost” during human evolution (as researchers often claim), we examined ovulatory cycle effects on tip earnings by professional lap dancers working in gentlemen's clubs. Eighteen dancers recorded their menstrual periods, work shifts, and tip earnings for 60 days on a study web site. A mixed-model analysis of 296 work shifts (representing about 5300 lap dances) showed an interaction between cycle phase and hormonal contraception use. Normally cycling participants earned about US$335 per 5-h shift during estrus, US$260 per shift during the luteal phase, and US$185 per shift during menstruation. By contrast, participants using contraceptive pills showed no estrous earnings peak. These results constitute the first direct economic evidence for the existence and importance of estrus in contemporary human females, in a real-world work setting. These results have clear implications for human evolution, sexuality, and economics.

I've not read the paper yet, but it's definitely provocative. I'm printing it out now.