A daylong photo shoot for Vogue pays only $150, women are like milk cartons, and other insights from the academic study of modeling.

There's a long tradition among academics of embedding in an occupation to study it. In the middle of the last century, social psychologist Marie Jahoda worked in an English paper factory to learn about about the lives of factory girls. More recently, sociologist Loïc Wacquant studied boxers by becoming one, while Sudhir Venkatesh spent seven years with a gang in the Chicago projects. One academic worked as a cotton picker, another entered prison as an inmate.

Ashley Mears embedded as a model. Then an NYU grad student in sociology, Mears had an idea what she was in for. She'd modeled in college, and knew that she still met the narrow physical requirements for the job. But this time around, she took notes after walking runways and attending casting calls. She interviewed other models as well as the industry tastemakers who hire them–agents, designers, magazine editors. Her new book, Pricing Beauty, offers a mostly grim picture of what's endured by those trying to make a living off their looks. Models are utterly dispensable, in Mears' telling: They labor at the mercy of inscrutable bosses, lousy pay, and punishing physical requirements. And for most of them, that's how the job will remain until they retire at the ripe old age of, say, 26.

Like actors and musicians, models work in a winner-take-all market, in which a few people reap rewards disproportionate to their talent, and everyone else scrapes by. This trend has become more exaggerated since the '90s, Mears writes, as the market has become glutted with young women from around the world, leading to greater turnover and plummeting pay rates. Would-be models are "scooped up, tried out, and spit out in rapid succession," she writes.

Through interviews, Mears investigated the financial state of the (unnamed) small modeling firm she worked for in Manhattan. * She found that 20 percent of the models on the agency's books were in debt to the agency. Foreign models, in particular, seem to exist in a kind of indentured servitude, she writes, often owing as much as $10,000 to their agencies for visas, flights, and test shoots, all before they even go on their first casting call. And once a model does nab a job, the pay is often meager. Mears herself walked runways, sat for photo shoots for an online clothing catalog, modeled for designers in showrooms, and went on countless unpaid casting calls. During her first year of research she worked mornings, evenings, and weekends around her graduate classes and earned about $11,000.

Why do so many models operate against their own economic interests? Mears details how, in the fashion world, there is typically an inverse relationship between the prestige of a job and how much the model gets paid. A day-long shoot for Vogue pays a paltry $150, for instance, while a shoot for Britain's influential i-D magazine, which Mears calls "one of the most sought-after editorial clients for a model," pays absolutely nothing, not even the cost of transportation or a copy of the magazine for the model's portfolio.

The alternative to high-fashion poverty is to be a "money girl," working for catalogs and in showroom fittings, jobs that pay well and reliably. The best-paid model at Mears' agency, for instance, was a 52-year-old showroom model with "the precise size 8 body needed to fit clothing for a major American retailer. She makes $500/hour and works every day." But the commercial end of modeling is widely derided within the industry as low-rent, as mere work without glamour. Once a model has done too many commercial jobs, she is thought to have cheapened herself, and it's exceedingly difficult for her to return to high fashion.

So many models operate against their short-term interests, hoping that by investing time now they will hit pay dirt later in the form of fame and a high-paying luxury ad campaign. The catch is that there simply isn't much time to invest; the older a model gets, the more she "exudes failure," Mears writes. She quotes a 23-year-old model who'd been instructed by her agency to say she was 19: "They said it's like when you go to the grocery store to buy milk, which milk carton would you want, one that is going to expire tomorrow or one that will expire next week?"

The funny thing is that even though Mears knew the odds were against her, and despite her academic ambitions, she, too, found herself drawn in by the fantasy that the big time was just around the corner. In her mid-20s, she was ancient by industry standards, but she kept modeling for almost three years after her re-entry into the field, well after she had enough material for the dissertation that would later become this book. Each phone call she got from her booker, ordering her to hustle across town right now to a casting, felt like the phone call that might change her fate. (Which begs the question, if even Mears could be seduced by the industry, what chance does a poor girl from rural Brazil have?)

"It's the lottery," Mears told me recently over tea at a West Village coffee shop. Now 30, still lithe and luminous in that otherworldly model way, she's an assistant professor of sociology at Boston University. "You realize that the probability is slight but the possibility is so enticing."

There are a number of academics studying the modeling life right now. As a subject for scholarly study the topic may seem slight, but then again, there's been an explosion in what might be termed "girly" studies—looking at the work of strippers and Playboy bunnies, for instance—going back at least as far as the popularity of Madonna studies 20 years ago.