On the supply side, for innovation, you'd say, go look at those R&D budgets, and they haven't moved in the last 20 years. In the case of the US - which is the majority of R&D funding across every category you can name: health, energy, whatever - it's been about $5 billion a year from the Department of Energy.

I have drifted away from thinking about these philanthropic things. And it was only as the wealth got large enough and Melinda and I had talked about the view that wealth wasn't something that would be good to just pass to the children.

Instead of buying airplanes and playing around like some of our competitors, we've rolled almost everything back to the company.

... No one is less happy than I am with the performance of Microsoft stock! I've lost tens of billions of dollars this year - if you check, you'll see that's more than most people make in a lifetime!

Americans want students to get the best education possible. We want schools to prepare children to become good citizens and members of a prosperous American economy.

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.

Bitcoin is mostly about anonymous transactions, and I don't think over time that's a good way to go. I'm a huge believe in digital currency... but doing it on an anonymous basis I think that leads to some abuses, so I'm not involved in Bitcoin.