K to 12 is partly about babysitting the kids so the parents can do other things.

We can make market forces work better for the poor if we can develop a more creative capitalism-if we can stretch the reach of market forces so that more people can make a profit, or at least make a living, serving people who are suffering from the worst inequities. ... You have more than we had; you must start sooner, and carry on longer.

It's OK for China to invent cancer drugs that cure patients in the United States. We want them to catch up. But as the leader, we want to keep setting a very, very high standard. We don't want them to catch up because we're slowing down or, even worse, going into reverse.

How much further beyond basic research the role of the government should be, you could have a really good debate about it. Almost nobody would say it's zero. But that's where at least we need the private sector to play a big role.

Going out in the field, it's always enlightening to see what's working and what's not and to sit down and talk - I was with young girls in south Africa - understanding why our tools for prevention aren't being adopted, and what way may need to invent to help protect them.

There's nobody getting rich writing software that I know of.

My success, part of it certainly, is that I have focused in on a few things.