You feel like you’re in romantic purgatory.

It’s real. It’s not a hazy paranoia.

And it’s not a matter of being too fat or too loud, too timid or too aggressive, too slutty or too frigid. If you’re a single, college-educated woman in Manhattan, the cards of love are stacked in favor of you remaining single—but it has nothing to do with texting a guy too soon or (not) sleeping with someone on a third date.

As financial reporter and author of Date-Onomics: How Dating Became a Lopsided Numbers Game, Jon Birger puts it, “It’s not that He’s Just not That Into You. It’s that There Aren’t Enough of Him.”

In his book, Birger eloquently explains, in terms that even the non-statistically-literate can comprehend, that the gender ratios of college graduating classes in the past few decades reveal that there really aren’t enough single guys. The “man deficit” is real for the graduate set. The current college class breakdown of women to men is 57:43, which means that there will be about one-third more women than men with college degrees when graduation arrives.

If we assume these women will want to marry college-educated men—a desire that Birger convincingly argues should and will change—there’s simply not enough men to make all those trips down the aisle a reality.

Recent debates about dating and sex have been seriously lacking in data. We’ve argued about hookup culture and whether it brought the death of monogamy and marriage, and about whether feminism and sexual liberation—giving women control over their reproductive health and sexual expression, while freeing them from the confines of a virgin ideal—could be considered the cause. But we’ve never really looked hard at the demographics—which may provide a far better, more concrete answer.

Birger points to a relatively overlooked book, Too Many Women?:The Sex Ratio Question, which was written by professors Marcia Guttentag and Paul Secord, and published in 1983. Guttentag and Secord noticed there was an over-supply of young, single women when the Women's Liberation movement and the sexual revolution blossomed. Further research showed that societies tended to skew away from monogamy when men were in scarce supply.

"The sexual revolution and the hookup culture... are both rooted in a statistical over-supply of women," writes Birger. This conclusion that people should lay off of feminism as the culprit for hook-up culture is not the focus of Date-Onomics, but a rewarding one for anyone tired of hand-wringing about whether feminism “hurts” women.

Birger focuses on the admittedly (by his own account) limited college-educated set and adroitly outlines that the disparity has been building for decades, but without us ever fully recognizing its influence. He crunches data from the National Center for Education Statistics (and includes very helpful charts in the appendix) showing that 1981 was the last year that more men than women graduated from a four-year undergraduate program.

Not for nothing are there 39 percent more women ages 22 to 29 with college degrees in Manhattan than men in the same bracket, with a gap of 100,000 between female and male college degree holders under the age of 35 in the entire city.

And while the land of Sex and the City is tough for single women seeking college-educated men, it’s hardly the worst. Fort Lauderdale has 71 percent more female college grads than male between ages 22-29, followed by Providence, which has 60 percent more.

The gap’s impact on dating for straight, single women is exacerbated, Birger explains, because men with college degrees are consciously or subconsciously aware that they are in scarce supply. They take advantage of their rarefied status by holding off settling down and enjoying the market of riches—and Birger’s book includes colorful anecdotes. One woman recalls a boyfriend who felt entitled to grope her friend right in front of her because he thought he deserved a threesome. Then there’s Jason Hendriks, the pseudonym given to a 34-year-old on the Upper East Side of Manhattan who is a “little pudgy and not the world’s sharpest dresser,” by Birger’s account.

Hendrik not only engages in the delights of not texting one-night-stands and ditching women who don’t immediately agree to have sex with him, but also loves playing women off each other by insulting others to manipulate them into feeling special. In short, he is a total asshole who plays off the insecurity of the numbers games to solely satiate his sexual desires.

When I speak with Birger, he assures me they weren’t all as bad as Hendriks.

“I didn't get the sense they were all being Machiallevian about it,” he says. “I think some thought that they were so special that they had just become really good catches, and that’s why they had so many options.” Yeah, right.

These men have the problem—or, really, the luxury—of the “paradox of choice.” It’s harder to commit to just one lady because they believe another woman will always be a little better.

“If they had a girlfriend they liked, but someone else came along who was a little smarter or prettier, a little more this or that, it was easier for them to call it quits because they had other options,” Birger explains.

But despite these stark numbers and sobering (yet familiar) stories, the joy of reading Date-Onomics comes, in part, from the fact there is something so satisfying in knowing you’re a bit fucked, but it’s not your fault. His data provides concrete, liberating evidence that we should stop over-analyzing the nonsense minutiae of modern dating.

“There are all these dating books that say how quickly you call or text is really going to determine whether you end up with Mr. Right or not. If you just think about it intellectually, it's stupid,” he tells me (to my glee).

“The idea that waiting an extra 12 hours makes the difference between being with Mr. Right forever and not, I mean it just doesn’t make sense, right? It’s not a strategic problem, it’s a demographic problem.”

In fact, the dating advice that is offered up in Date-Onomics runs refreshingly against the courtship narratives that are most restrictive for women.

For example, even in 2015, women are still often expected to “play hard to get” and “let men take the lead.” Women who don’t demurely wait to be fawned over are often branded as “desperate” or “pathetic.”

Birger counters these women are not, in fact, desperate. They’re married because they took fate into their own hands—which is all the more needed when the numbers are so against you.

In seven of the couples, the woman pursued the men.

“It’s decisive women who, maybe, odds-wise are more likely to get the guy,” Birger tells me. That’s because “guys don’t like to be rejected. They would rather not take their chance than put themselves out there and get rejected.”

There were moments when Date-Onomics is initially disheartening—especially if you’re a 25-year-old woman who takes comfort fantasizing the perfect guy is out there and you just haven’t found him yet.

“For a college-educated woman who puts an extremely high-priority on getting married to a college-educated man, she may be better off strategically—though not necessarily romantically—getting married young to Mr. Perfectly Acceptable rather than holding out to 40 for Mr. Right,” Birger writes. My initial response to this was panic. But, as occurred so many times reading Date-Onomics, I ultimately felt liberated, fear replaced by the realization that driving yourself crazy to find some mystical “best”—and, in turn, to attract that mystical “best”—was a waste. It’s a passage I proceeded to share with nearly every friend on Gchat.

In the hands of a patronizing writer, or worse, a smug married person, Data-Onomics content would be hard to digest. However, it’s abundantly clear that Birger comes from a place of respect. Perhaps because he’s not only an outsider in terms of his financial reporting background but as a suburban father of three who has been married for 20 years.

When I ask Birger how he began exploring the “man deficit” when he’s been out of the dating world for decades, he says his female colleagues and friends were his motivators.

When a work friend in her late thirties mentioned that she and her boyfriend, a man in his mid-forties, broke up because he wasn’t ready to settle down, her visible sadness left Birger feeling frustrated enough to investigate what he had long pondered: Why were his amazing female friends and colleagues single after years of dating and seeking marriage?

“I had this initial reaction of exasperation,” he said. “I just know all these women who have so much going for them and their self-confidence has been shot by being in cities, like New York City. It’s terrible women are making these strides, and this minority of men who are college-educated are benefitting from something over which they have no control.”

He is fairly optimistic that the dating culture will change once people are aware of the demographics realities.

“As a financial writer, I see that there are all sorts of examples of market inefficiencies that people can exploit only because the people participating in them are the only ones who know about them,” Birger tells me. “Ones they’re exposed, people’s behavior changes.”

In Date-Onomics, he cites how baseball changed after Michael Lewis’s Moneyball exposed Oakland A’s general manager Billy Beane’s strategy of picking up hitters with high on-base percentages because they were undervalued. Only a few years after the book’s publication, the “cost of acquiring such hitters via the free agent market soared.”

Birger does have a few suggestions for improving one’s odds as a college-educated woman looking to marry.

One is simply “Go West, young woman.” Move yourself into man-heavy tech enclaves, like Silicon Valley. California, Colorado, and Washington tend to be states with gender ratios friendlier to women. In Santa Clara County among the 20-29 age group, there are 38 percent more single men than women and 48 percent more single men than women in the 30-39 group, The county tends to have fewer divorces, too—another upshot of men being scarce.

But a big move may not be possible for someone with a full career and social life—and Birger understands that this suggestion is untenable. Besides, it’s a relatively superficial response to the larger root of the college gender gap, a problem that affects so much more than dating: Boys are lagging behind in higher education.

“More boys need to go to college. That’s the long-term solution,” Birger says.

“I am certainly not suggesting we do it at the expense of girls. I just think there’s a boy problem we need to address. There shouldn’t be 35 percent more women than men in college.”

This disparity is not exclusive to the U.S.—Birger notes that the U.K., Australia, Israel, New Zealand, and many other developed countries have similar college gender disparities—but the ramifications go far beyond courtship.

“Forget about dating. It’s really about the economy,” he says. In Date-Onomics, Birger cities a study conducted by Columbia Business School professor Shang-Jin Wei and economist Xiabao Zhang showing that “20 percent of China’s GDP growth from 2000 through 2005 was attributable to the oversupply of men.” With women in China in short supply, the eligible bachelorettes made it clear that they prioritized guys with cash—which in turn, may have fueled the economy.

At the same time, men and women should both be less resistant to what Birger refers to as “mixed-collar marriages,” i.e, doctors, lawyers, and bankers marrying people without college degrees who work in blue-collar professions.

“It’s a problem that we, as a society, are not more open-minded about who we are willing to date and marry. I was trading emails recently with a dating book author, and he made this comment that classism is a bigger problem in dating than racism. I agree,” Birger says.

By confining themselves to degree-holders, Birger argues that women are “limiting their options and giving those college grad men too much leverage.”

“I can’t accept the idea that a guy who doesn’t have a college degree means you’re marrying down. That’s a classist thing,” he says, rather adamantly.

It’s one of the strongest directives to come from a man who is hesitant to peddle too much specific advice when it comes to finding “the one.” As he often does during our interview, Birger places heavy caveats on his counsel, noting he’s not a dating coach or matchmaker.

“I’m not a dating professional,” he says. “Who wants to take dating advice from a financial writer?”

Well, I certainly do—and maybe so should others.