You can be a business thinker.

I admire leaders in science, people who really figure things out like Richard Fineman or people who work on vaccines, tons of people working on [the] HIV vaccine. There's leaders in business, people like Warren Buffett, who've got a certain approach they take that are pretty amazing. There [are] product innovators like Steve Jobs was, where he gets behind a concept and does a fantastic job.

Innovation is often the hidden thing, because we can't put numbers to it. And yet it's the thing that defines the way we live, the things we'd like to have for everyone whether it's health or education.

For one thing, there's an essential human factor in every business endeavor. It doesn't matter if you have a perfect product, production plan and marketing pitch; you'll still need the right people to lead and implement those plans.

In the philanthropy game, you're going for different outcomes: saving childhood lives, having kids grow up - because they don't have malnutrition or disease - that they achieve their full potential. We take for Warren [Buffett] things that, because he's very intelligent about the world but doesn't get to go out in Africa and see what we see, we've taken and say to him where we stand and it's basically a very positive report that his gift has made a phenomenal difference.

Like my friend Warren Buffett, I feel particularly lucky to do something every day that I love to do. He calls it "tap dancing to work."

Our work in global health is about things like cutting childhood deaths, and every year we continue to make progress there.