A FEW years ago, I attended a party at a nightclub in the meatpacking district of Manhattan with about 10 young women, most of them models, and two club promoters, men whose job was to bring beautiful women to exclusive parties. Beyoncé’s hit single “Run the World (Girls)” boomed, and the girls danced to the beat, singing, “Who run the world? Girls! Girls!” One promoter joined in, with his own twist on the chorus: “Who run the girls? Boys! Boys!” The men high-fived, and everyone laughed.

Many of the models who walked the Fashion Week runways this month in New York, London, Milan and, starting this week, Paris, are the same women who pass through these clubs. The fashion shows and the international circuit of V.I.P. parties — Miami in March, Cannes and St.-Tropez in May and July, August weekends in the Hamptons — serve as case studies in an old debate. Does the celebrated display of female beauty and sexuality empower or exploit women?

V.I.P. night life is an industry run by men, for men, and on women, who are ubiquitously called “girls.” The girls are brought in to attract big-spending clients from among the young global elite, willing to spend thousands of dollars on alcohol. Hence the V.I.P. party is sometimes half-jokingly described as “models and bottles.” The girls are seen as interchangeable; one club owner calls them “buffers” because rows of them frame his Instagram party pictures. They are recruited through friends of friends, scouted on the streets of SoHo, with its clusters of fashion agencies, or tracked down at model castings.

During the week I was a sociology professor. But during my weekends and summer vacations, I became one of these girls. In exchange for showing up at their parties, the promoters let me study them. I was what they call a “good civilian” — close enough in physique but not as valuable as a fashion model.