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.

I'm a big believer that as much as possible, and there's obviously political limitations, freedom of migration is a good thing.

[We in Microsoft] are not the only software company but we are a great software company doing some unique work.

The US spends more on energy R&D than all other countries put together, and I personally consider it quite inadequate. In fact, I would have said we should more than double it, if I thought the absorptive capacity could scale up and if it was actually possible to get to that level.

Energy is very primal stuff and there are a lot of leads that are promising, still at a fairly risky stage, but over the next decade some of these breakthrough approaches are going to pay out, and U.S. research and U.S. leadership on this should be part of how it gets solved.

If we [the USA] don't innovate in education, it's literally going to mean less people get to go have that education at a time when more people are going to want it. We've got to put courses out on the Web, we've got to put interactive learning out on the Web.

Taking a look back, one big reqret is, I left Harvard with no real awareness of the awful inequities in the world. The appalling disparities of health and wealth and opportunity that condemned millions of people to the lives of despair. I learned a lot here at Harvard about new ideas and economics, and politics. I got great exposure to the advances being made in the sciences. But humanities greatest advances are not in its discoveries, but in how those discoveries are applied to reduce inequity.