Mining the 'big data' of sex

Why lesbians make more money.

dollars and sexMy older brother spent much of his 20s as many in my generation do, working at different jobs in different lines of work, waiting for something to stick. He wanted to be a doctor at one point and did a science degree. Later, he was a bouncer, and he worked in real estate during the hottest years of Calgary’s last boom. But as he grew older, his priorities shifted. And in his late 20s, he went back to school and completed an MBA.

It was around that same time that my brother met his future wife. She was already a successful corporate accountant. And by the time they married, last summer, he too was settled into a career in corporate banking. Today, my brother and his wife are thriving, happy and, if you believe Marina Adshade, one of the big reasons why income inequality continues to grow in this country.

Compared to previous generations, today’s well educated, high-earning professionals are much more likely to marry later and to people more like themselves, Adshade writes in her new book, Dollars and Sex. Forty years ago, a doctor (or a lawyer or banker) might have married his high-school sweetheart. Today, they’re waiting longer and marrying other doctors, lawyers and bankers, effectively doubling their family incomes and helping pool more wealth at the top of the chain. It’s all part of what Adshade describes as the economic market for dating and love. For those at the top, the market is expanding, making it easier for people to form couples where both partners are earning at similar rates and helping make the gap between rich and poor larger than it has ever been.

Adshade, who teaches economics at the University of British Columbia, has in recent years carved a niche for herself as the Nate Silver of knocking boots. Her blog, also called Dollars and Sex (it lived for a time at is a deep well of economic research on marriage, dating and just plain screwing around. Adshade converted the best of that work—and more—into Dollars and Sex, her first book.

Some of the research she writes about comes off a bit warmed over. (I don’t know if you’ve heard, but women outnumber men on university campuses these days.) But much of it is surprising—at least it was to me. I did not know, for example, that lesbians are, on average, paid wages about 6% to 13% higher than wages paid to heterosexual women. That gap persists even after researchers correct for the fact that openly gay women are, on average, better educated, more likely to be white, live in a city and not have children, than are heterosexual women.

Another revelation: there is a significant correlation between college tuition fees and risky sexual behaviour in high-school students in the United States. According to work by the economist Benjamin Cowan, reducing the price of a community college education in a state by $1,000 also decreases the number of sexual partners the average high-school senior has by 26%. Cowan has also found that teens are less likely to smoke cigarettes or marijuana in states where college is affordable.

As a good economist, Adshade explores market-based theories for all of her anecdotes. Researchers still can’t explain the lesbian wage gap, she writes. But they’re pretty sure there’s a cost-benefit analysis behind the tuition-fee, sex-partner link. High-school students who feel they can afford to pay for college have more to lose by getting pregnant when they’re in high school than those who don’t, the theory goes, so they’re more reluctant to do something that could jeopardize their future success.


In her new book, the very clever Amy Webb describes how she used algorithms to game the online dating system and find her perfect mate online.


Some of the studies Adshade examines in her book get spun into entire chapters, such as those on marriage and dating among the elderly. Others appear as shorter vignettes, with titles like “Cheating As a Problem of Dynamic Inconsistency.” As I made my way through them, I was struck by just how much of Adshade’s work relies on data gleaned from online dating. In fact, as recently as 10 years ago, a book like Dollars and Sex may well have been impossible to write. Good economic research relies on observations from markets in action, and before Internet dating became popular, reliable data about dating and love was notoriously hard to come by. Today, though, researchers have a massive pool of information—call it the Big Data of sex—on what people are actually choosing, not just whatever personal fictions a subject writes into a survey box.

Adshade mines that data to mostly good effect. For example, in surveys people tend to downplay how much salaries or good looks matter to them in a partner. But online, Adshade writes, when it comes to actually choosing to contact or date someone, both are extremely important. That’s not totally surprising. But this is: according to one Oxford University study Adshade discusses, a seriously unattractive man would need to earn $186,000 more than a truly attractive one for women to prefer him online. On the other hand, an unattractive woman (as judged by other users), could never earn enough money for men to prefer her over a good looking one. “Either men care so much about appearance, or so little about income,” Adshade writes, “that it is impossible to financially compensate them sufficiently to make that choice.”

That may sound harsh, but that’s Adshade’s greatest strength. As a writer, she is blissfully unsentimental about her material. She’s interested in people’s choices, not in judging them. And by viewing everything through a market lens, she avoids the kind of panicky moralizing about sex, love or marriage that infects other writing on the subject. “People marry for a variety of reasons,” she writes, “but from an economic point of view the purpose of marriage boils down to two things: efficient production of household goods and services, and insurance in bad times.”

The pleasure of reading Dollars and Sex, in other words, is that Adshade doesn’t have an agenda to push, nor any Gladwellian “Aha!” moments to neatly package. The book is a clever collection of small conversation-ready revelations packaged in an accessible way: like a first-year course in economics, with sex thrown in to keep everyone awake.

Richard Warnica is a staff writer at Canadian Business. He’s looking for a $186,000 raise