When it comes to that headline gender wage gap figure we all know so well — that full-time working women earn 78 cents for every dollar that men earn — there's a huge population of doubters.
Readers often remind me of this when I write about the gender wage gap. It's not fair to say that women make 78 cents on the dollar, one of the big arguments goes, because so much of that is about women's choices: more women choose to go into lower-paying fields, picking jobs and majors in education while men generally pick high-paying careers in engineering and tech.
A new working paper from the National Bureau of Economic Research suggests that something else might be at work here shaping the supposed "choices" girls and women make. It shows that young girls' teachers have biases that push girls away from math and science early on, which could be influencing where they go later in life.
Economists Victor Lavy from the University of Warwick in the United Kingdom and Edith Sand from Israel's Tel Aviv University looked at Tel Aviv sixth graders' test scores both on standardized tests and internal tests in Hebrew, English, and math. The economists considered the difference between the internal tests (graded by a teacher who was aware of a given student's gender) and external tests (graded by outside assessors who didn't have student information) a measure of a teacher's bias — in this case, their attitudes about girls' and boys' different cognitive abilities.
They found that in sixth grade, girls underperformed in math in particular, relative to boys, when graded by their own school's teachers. Researchers concluded from their results that teachers had a "systematic bias against girls in the marking of math exams" — their scores overstated boys' math skills and understated girls' skills.
That gap had major effects just a few years later. The researchers then looked at these student's exams in eighth grade and in high school, as well as their enrollment in advanced courses in high school. Girls outscored boys in sixth grade, but they lost that lead later on. After controlling for other factors, researchers concluded that those early teacher biases led to significant improvements on the later math exams for boys and negative and significant effects in math for girls. There were similar effects on the likelihood of completing advanced math courses: positive for boys, negative for girls. That's particularly important, the authors write, because those advanced courses are prerequisites for studying fields like engineering and computer science in college.
As with any study, there are a few caveats: this is a working paper, meaning its results are preliminary, and it studied students in a different culture and school system, so we can't assume US students would see the exact same magnitudes of effects that the Israeli students did.
Nevertheless, it is evidence of the power of biases — discourage a child from pursuing a subject, and she will, years later, later perform worse on that subject (encourage her, meanwhile, and she'll do better). So when you discourage a whole swath of the population from pursuing high-paying fields, all those people will be much more likely to have lower-paying jobs.
Indeed, socialization takes hold early. Organizations invested in getting young girls interested in math and science struggle to do so. When a Pittsburgh science museum was criticized last year for holding a makeup workshop for Girl Scouts alongside robotics and engineering offerings for boys, the museum responded that it had tried offering girls those sorts of science events, but girls weren't interested.
And this sort of phenomenon has big implications for the gender wage gap debate. College majors are hugely important in determining future pay. Men tend to dominate in engineering fields, one of the highest-paying for early college graduates. More women, meanwhile, dominate in social work and education, which are low-paying fields.
This isn't just a problem for women; it's a problem for society. This study suggests that girls were just as capable as boys at math at the start of the observation period, but they were slowly pushed away from math. To diminish an entire demographic's talent at once is to squander their potential productivity, and economic growth.
Of course, there are lots of factors that go into the wage gap. Claudia Goldin, for example, has found that even in some of the highest-paying fields like finance and law, women fall far behind in pay, because those fields reward long hours — hours that women, saddled with childrearing and homemaking responsibilities, find harder to work than men. There's also evidence that women aren't as skilled at negotiating salaries.
But all these factors together reflect profound, entrenched inequalities in society. Make no mistake: women really do make 78 cents for every dollar men make, and that gap — all of it — signals that something is wrong.