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.

After a number of years dating, we decided we were good partners.

In places like India with smartphones, there's an app now for women if they're in a violent situation, they can press one button. They've given their cell-phone number to five trusted friends, and right away their GPS location goes out: "Here I am."

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.

When we better understand the realities of these women's lives, we are able to design and deliver solutions that are more useful to them.

Women are the centre of the family. It's the woman who decides what's eaten in the house, when to have the kids vaccinated; everything that has to do with the children's health revolves around her.

Sanitation issues in the developing world affect women more than they affect men.