Like in Africa, if somebody doesn't have fuel, they're still going and collecting firewood. If they get an oven, that's a huge difference. You can do things to reduce the inequities by making sure that they can get clean energy, safe energy. To make sure they're not having to collect water every day. That's huge for women in the developing world.

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.

Mothers might say they'd go to the doctor. In poor countries, moms are usually responsible for their kids' health. But breastfeeding and traveling to the clinic take time, and research shows that health care is one of the first tradeoffs women make when they're too busy.

The biggest pieces of work that we do are vaccines, because those save lives, and also family planning. Because if a woman can space the births of her children, it changes everything for her health and her child's health.

Abortion has become a very politicised issue that I think countries have to work out themselves. In a lot of countries, people can't even yet agree on what their laws should be.

Around the world we have girls in primary school at about the same rate now as boys, but keeping them in quality secondary schools is where the world is lagging. I'm seeing a lot of countries look at this now.

Government funding that's coming from the United States is making a huge difference on the ground in the developing world. It's really palpable - it's making a huge difference saving lives.