Well depending on the government, you either work through the government, which is ideal, because then you're strengthening their capabilities, or you work through the non-governmental organizations. It's never easy, and you know, it's just about the very basics of health. This is not hospitals. This is just primary health care [in Africa], the most simple things, and even so, getting the supplies out, getting the trained workers there.

You know capitalism is this wonderful thing that motivates people, it causes wonderful inventions to be done. But in this area of diseases of the world at large, it's really let us down.

The genius of capitalism lies in its ability to make self-interest serve the wider interest. The potential of a big financial return for innovation unleashes a broad set of talented people in pursuit of many different discoveries. This system, driven by self-interest, is responsible for the incredible innovations that have improved so many lives.

If you think your teacher is tough, wait till you get a boss.

Me and my dad are the biggest promoters of an estate tax in the US. It's not a popular position.

Online education is pretty special for two reasons. One is that you can get the very best lecture in the world and wherever you are, whenever you want, you can connect to that lecture. The other is this interactivity, where if you know a topic, you can kind of skip over it. Or if you're confused about it, [the area] where you're confused can be analyzed by software.

Lectures should go from being like the family singing around the piano to high-quality concerts.