In the developing world, they don't have smartphones yet. They have the older plastic phones, but women are saving money on those, because they don't have access to banks. Having that access to digital money changes everything for her because she actually doesn't have to negotiate with her husband, which she will tell you is very hard in these circumstances, especially when the means are meager. She's expected to have money to pay for the kids' health or to help with the school fees.

I realized that the only way to get into a good college was to be valedictorian or salutatorian. So that was my goal.

Bill [Gates] and I believe philanthropy can only be effective if it starts things and proves whether they actually work or not. That's the place that governments often don't want to, or can't, work.

When girls are educated and free to pursue their passions, they contribute more to a thriving society. When women have a voice, they raise it to demand a life that is greater than what they've been told they have a right to expect. And these demands change the future for everyone.

We have to look at it country by country. In places like the developing world where, as you say, in Mumbai, it's about five hours' gap between what a woman does and a man does. You have to start by recognizing the problem and talking about it, trying to change those roles.

If you ask, who has the chance to move into the city and get a good job out in the developing world? It's a man. Who's left to care for the kids back at home? The woman is.

I'm constantly saying to myself, 'I'm lucky I was born in the United States.