Melinda Gates and her kick-arse rule about housework.

Every society relies on unpaid labour to function, whether it’s cooking, cleaning or caring for children, all of these things must be done and they must be done by someone.

Unfortunately for women all over the world, it’s usually them.

According to Melinda Gates it’s “the gender gap no one is talking about” and it needs to be redressed, urgently.

“Unpaid work is what it says it is: It’s work, not play, and you don’t get any money for doing it. But every society needs it to function,” Gates writes in her half of the annual letter from herself and husband Bill.

In the Gates’ household there’s a rule: “Nobody leaves the kitchen until Mom leaves the kitchen.”

When she first introduced it, suffice to say, it wasn’t immediately popular, but Melinda was tired of doing the chores, simply because she was matriarch and her husband and three children quickly adjusted.

“It’s not just about fairness; assigning most unpaid work to women harms everyone: men, women, boys, and girls,” Gates writes.

“Globally, women spend an average of 4.5 hours a day on unpaid work. Men spend less than half that much time.”

She adds that the burden of unpaid work is far greater for women in the developing world.

In India, for example, women spend about six hours while men spend less than one.

“I know from listening to my kids and their friends — and from looking at polling data about how teenagers see the future — that most girls don’t think they will be stuck with the same rules that kept their grandmothers in the home. And most boys agree with them.

“I’m sorry to say this, but if you think that, you’re wrong. Unless things change, girls today will spend hundreds of thousands more hours than boys doing unpaid work simply because society assumes it’s their responsibility.”

Melinda Gates on relieving the burden of “time poverty”.

The result is a worldwide “opportunity cost”,  Gates explains, as women miss out because they’re stuck managing the domestic sphere:

“What amazing goals would you accomplish with an extra hour every day? Or, in the case of girls in many poor countries, an extra five or more?”

Girls might use the time to do their homework, their mothers might go to the doctor, she speculates, “some women might simply read a book or take a walk or visit a friend.

“Everybody’s better off when more of us are fulfilled in our daily lives.”

You can read the letter in full here.