All these questions tie into Goldin’s career focus: women’s participation in the workforce and the barriers to gender equality, for which she received the Nobel Prize in economics on Monday.

In an early paper Goldin published with Lawrence Katz, her husband and frequent collaborator, the Harvard economics professors pinpoint one explanation for women’s surge into higher education and the workforce in the 1970s: the birth control pill. 

First patented in 1955, the pill didn’t become widely available until the early 1970s, through a combination of state and federal law changes that lowered the age of legal adulthood to 18 from 21. Initially passed as a response to criticism of the draft (under which 18-year-olds who couldn’t vote could still be enlisted to fight and die in war), the law had the secondary effect of letting millions of young women access contraception without parental permission. That drug, in combination with new laws and the women’s rights movement, supercharged female participation in work and public life. Between 1970 and 1980, the number of women in law schools more than tripled, the number of women in business school increased 10-fold, and the share of women who married before age 24 plummeted, from nearly half to less than 30%. 

The pill “allowed women to postpone motherhood and get more return from their investment in the workforce,” said Martha Gimbel, a research fellow at Yale Law School and former White House economist.

“If…you think you’re going to start having children and not working as much, going to school might not make sense for you—you won’t get that much return from your investment,” Gimbel told Fortune. “But if you can control your reproductive future, and choose to delay having children, it now makes more sense for you to go to medical school.”

But it wasn’t just good for women who could suddenly choose careers, Goldin and Katz suggested. By making sex without marriage (or the consequences of pregnancy) easier, the pill allowed young people to “try before you buy,” letting them be choosier with their eventual spouse and ultimately leading to longer-lasting marriages, the authors posit. 

How orchestras hire

Another early paper of Goldin’s, coauthored with Princeton economist Cecilia Rouse, looked at the role of sex discrimination in hiring musicians. The paper demonstrated that once symphony orchestras began holding blind auditions, in which job applicants were hidden by a screen, the portion of female musicians hired dramatically increased.

“In retrospect, it’s so simple, so clean. But nobody had thought of it before,” said Gimbel of the paper. “Simplicity in economics is really hard to achieve.”  

Goldin’s work also often revealed counterintuitive findings. Before Goldin began researching 200 years of women’s workforce participation, the Associated Press wrote, many economists had simply assumed that as nations developed from agrarian to industrial societies, the share of women working gradually increased.

But after painstakingly compiling her own databases and sorting through historical records, which often undercounted women who worked on farms or in cottage industries, Goldin’s research found the opposite: Married women’s working participation was U-shaped over the past two centuries, the Nobel committee wrote. As the U.S. and Europe entered into the Industrial Revolution, women’s share of the workforce actually dropped, only to rise again later as the service sector grew. 

Greedy families, greedy jobs

Goldin’s work also demonstrated the evolving nature of the gender pay gap—which has narrowed over the years but hasn’t disappeared, with women in the U.S. today earning about 18% less than men. In decades past, much of this gap was explained by the differences between traditionally higher-paying male jobs (construction, manufacturing, law enforcement) and traditionally lower-paying female jobs (teaching, nursing, social services). But today, Goldin’s research shows, it’s largely due to childbearing.

Goldin, 77, showed that in high-achieving couples, “women often step back, and the men in their lives step forward,” she told Planet Money in 2021. 

Goldin coined the term “greedy jobs”—high-paid work in technology or law that expect workers to be available at unusual times, such as Sunday nights, dinners, or vacation. The nature of these jobs forces couples to split their time, with the wife, most often, choosing to be on family duty at home (to the detriment of her career), and the husband leaning in at work. As Planet Money reporter Stacey Vanek Smith points out, that’s the financially logical choice that allows the family to maximize its earnings, but, repeated over thousands of high-earning couples, it perpetuates the financial gap. 

The Nobel Foundation praised Goldin’s work for revealing some of the causes of the gender gap—and how stubbornly difficult some of them can be to eradicate. It’s not enough for women and men to have the same level of education, for instance. Today’s gap in pay persists despite women outdoing men in college and graduate school enrollment. 

“She’s pushed into these areas that are really existential,” Gimbel said. “Greedy jobs, there’s not a simple solution to that. You can’t just put up a screen for the audition.” 

She added, “Gender equality at this point is so much around cultural norms and expectations, and that’s really hard to address.”