looks a little different depending on how you measure it.

In Poland, women earn 91 cents for every dollar a man does.

In Israel, it's 81 cents.

In South Korea, women make just 65 cents on the dollar.

We know that just freeing the potential of women,

that is the fastest multiplier that we have in terms of our growth.

That is such an accelerator in eradicating poverty.

When you go to the store, you don't get a woman's discount.

You have to pay the same as everybody else.

So that comes out of your family income.

[McAdams] When someone mentions the pay gap,

you often hear another phrase as well.

-Equal pay... -...for equal work.

-Equal pay... -...for equal work.

[McAdams] It makes it sound like women are paid less

for doing the same job as men,

which means women are paid less just for being women.

There's a word for that, discrimination.

But a huge body of research from many countries shows

that overt pay discrimination only potentially explains

a small part of the gender pay gap.

It's a real number, but it really, actually tells you almost nothing

about the real disparity between men and women.

Women aren't looking for a leg up. They want equal opportunity

and equal pay. Big difference.

If you want to change culture, you can't sit down and wait.

You must do something about it.

[McAdams] So, if it's not all about discrimination,

why are women around the world paid so much less than men?

[man] The woman who works at a career has chosen to ignore that the woman's place...

It doesn't matter if you have a female or male body,

they should be paid accordingly.

[man] I see some really advanced clerical work.

Pays women 80 cents for every dollar it pays men.

[woman] This is our time to stand up to have our voices heard.

And women will lead this country.

That's what this is all about.

[McAdams] The story in the United States is similar to a lot of countries.

It wasn't very long ago that most women, especially white women,

didn't work outside the home at all.

When you go back to the 1950s,

there weren't very many women in the workforce.

The women there were were often not as well educated as the men.

They either didn't finish college,

or they didn't have the same credentials in college,

or hadn't gone to college at all.

Most of the women in my neighborhood did not work.

My mother did not work.

The only women that I saw in professional roles were teachers.

[McAdams] Most women didn't get that far.

Seventy percent had menial jobs on factory assembly lines or in offices.

[man] Women workers don't mind routine, repetitive work,

and they're good on work that requires high finger dexterity.

[McAdams] People understood that a woman might need to earn a little money,

but a career? That was for men.

Your high score on the clerical aptitude test

indicates that you can become a good secretary.

[McAdams] Discrimination was also totally legal,

allowing employers to put out job listings for men only.

When I was growing up,

I knew one woman lawyer. One.

I never met a woman doctor.

I couldn't have even imagined women engineers.

[McAdams] The pay gap hovered around 60 cents on the dollar.

It was caused by several interconnected factors,

like lower female education rates,

women not being in the workforce in big numbers,

grouping in traditionally feminine industries,

and the fact that it was perfectly legal to pay women less,

and then a slew of cultural norms about gender roles and aptitudes.

These were the major explanations for the pay gap.

And then, in just a few decades, things changed.

Sisterhood is powerful! Join us now!

[man] The battle cry of the women's liberation movement

rings out down New York's Fifth Avenue.

[man] First woman to receive the highest honor of the National...

[man] The House broke into spontaneous applause.

Benazir Bhutto, the new prime minister.

[man] This is the first American woman in space.

[applause]

[man] First woman nominated to the Supreme Court.

[man] First woman ever to run on a Presidential ticket.

My candidacy has said to women, "The doors of opportunity are open."

Women are out-earning men in college degrees and advanced degrees.

[woman] Women are engaged to bring the next generation.

For the first time in history,

women are actually outnumbering men in the workplace.

This was just a sea change

to see women competing for scholarships I couldn't have competed for,

going to schools that were not open to women,

taking on jobs that were closed to women.

That's changed... just... unbelievably.

[McAdams] Many of the factors that were causing the pay gap shrunk,

except for one.

[Anne-Marie Slaughter] But what has stayed is that women bear children.

They are assumed to be the primary caregiver.

[McAdams] Even as women became doctors, and lawyers, and heads of state,

the popular expectation remained in society

that they would still do most of the work of raising children.

In the United States, in the UK,

even in progressive Scandinavian countries,

surveys today show only a fraction of the population

thinks women should work full-time when they have young kids.

When it comes to men, the expectation flips.

Seventy percent of Americans think that new fathers should work full-time.

There still is a considerable percentage of people,

not just in our country, but around the world, who really think

once you're a mom, you shouldn't be in the workplace.

And that's been proven wrong, short-sighted over and over again.

I learned, after I went back, when my time was constrained,

not by my employer, but by me,

because I wanted to get home to that baby and spend time with her,

that I could actually get a lot of work done in 15 minutes.

Like, I would take any opportunity to work.

I've become, I think, a much better employee since I've had children.

[McAdams] Even when a mother does work full-time just like her male partner,

she spends nine hours a week more than him on childcare and housework.

Over a year, that's the equivalent

of an extra three months of a full-time job.

This is the heart of the pay gap,

and to understand why, it helps to follow the story

of a young couple just starting out on their careers.

I often think about the trajectories

of the many law students I taught.

They look exactly the same.

They have the same educational record, the same experience.

And then you watch what starts to happen

as they hit their late 20s, early 30s, childbearing years,

and they start thinking about having children.

If they have children, at that point, somebody has to be home.

You can have lots of childcare,

but a parent needs to be at home for those situations that needs a parent.

So he's likely to get promoted.

She, on the other hand, has had to turn down some of those assignments,

say no to some of that travel.

So eight years out, ten years out,

typically, he's then a partner, and he can do lots of things from there.

She hasn't made partner. She's not earning the same.

She's working flexibly, or even part-time,

and from there, her earning potential and his just keep diverging.

[McAdams] This is the story the data tells us in study after study

in a variety of different countries.

One Danish study did an especially good job

of showing how childbirth affects earnings.

[McAdams] Here's a man's pay trajectory.

Watch what happens when his child is born.

Here's the woman's trajectory.

So then if you compare the earnings of a woman with kids

to a woman without kids,

you can see that the pay gap isn't as much about being a woman

as it is about being a mom.

The gender gap really is between women with children and everybody else.

Women who are not caregivers earn 96% of every dollar.

It's a motherhood penalty.

[McAdams] Some mothers don't see this as a problem.

They want to spend more time with their children.

They don't mind if it means making less.

Some women make a job choice based on the fact they want to have families.

Nothing wrong with that.

Presenting it as, you know, a penalty is kind of denying

first, that women make that choice,

but also that there's some extreme value...

not just for the children, the family, but also for the women making that choice.

A pay gap based on choices, you know, is different

than a pay gap that's just because you're a woman,

and you just can't get equal pay for doing the same thing a guy does.

[McAdams] But often, women and men don't get the same choices.

In the US, there are three times as many single moms as single dads.

And growing up, most of us get the message

that caregiving is more of a woman's job than a man's.

Take, for example, a 1980s advice column about how to decorate your desk at work

that still rings true today.

Someone wrote in and said, "I've just gotten a big promotion,

so I'll have my own work space for the first time.

How should I decorate it?" And here was the answer,

"I can't tell from your initials whether you're a man or a woman,

and the answer depends upon which you are.

If you're a man, and you have a family, plaster your office with family pictures,

because people will think you're a very good provider.

If you're a woman, and you have children,

don't put pictures up in your office of your family,

because people will think you can't keep your mind on your work."

[McAdams] The roots of this issue go deep to how we understand family

and mothers and fathers.

It's why the gap is so hard to close.

But it's not impossible.

Two countries, Iceland and Rwanda,

have almost closed their wage gaps, and in just a few decades.

And looking at these two cases reveals important lessons

about what it takes to create a society

where women are paid almost the same as men.

Rwanda is one of the poorest nations on Earth,

and until just a few decades ago, women were denied many basic rights.

[Consolee Nishimwe] Before 1994,

women were not allowed to speak in public.

Married women were not allowed

to open a bank account without the authorization of their husbands.

[McAdams] But in 1994, everything changed.

The fifth day of carnage and bloodshed in the Central African nation of Rwanda.

Thousands of people are feared dead tonight...

The fiercest fighting yet in the Central African nation of Rwanda.

[McAdams] In just three months, 800,000 people were murdered.

Losing my dad and my three brothers,

I survived with my mom and my sister.

[McAdams] After the violence, the Rwandan population was 60 to 70% women.

It destroyed completely the social fabric.

You do anything you can do to survive.

[McAdams] The shortage of men meant

that women had to step into the workforce in huge numbers,

taking on jobs that a year earlier would have been unheard of.

You'll find a woman who was police, for instance, or in the military.

Gradually, women were found, like, being a mayor, a governor.

Women actually were helping to change, you know, the country.

[McAdams] The new government realized that to rebuild Rwanda,

they needed women.

So they immediately implemented a host of new policies

aimed at getting more women into positions of power.

The preamble to the new Constitution

included a commitment to equal rights between men and women,

stipulating that 30% of representatives at all levels of government be women.

Today in Rwanda, women hold 61% of the seats in Parliament,

the highest in the world.

They have a labor force participation rate of 88%.

Rwanda is one of the few countries

where a woman is just as likely as a man to work outside the home.