In countries around the world, the ways in which men and women spend their time are unbalanced. Men spend more time working for money. Women do the bulk of the unpaid work — cooking, cleaning and child care.

This unpaid work is essential for households and societies to function. But it is also valued less than paid work, and when it is women’s responsibility, it prevents them from doing other things.

“This is one of those root inequalities that exist all over in society and we just don’t talk about it very much,” Melinda Gates, co-founder of the Gates Foundation, said in an interview. She said she was inspired by her own observations when traveling to other countries as well as by time-use data from the Organization for Economic Cooperation and Development. “If we don’t bring it forward, we basically won’t unlock the potential of women.”