Polio's pretty special because once you get an eradication, you no longer have to spend money on it; it's just there as a gift for the rest of time.

Eradications are special. Zero is a magic number. You either do what it takes to get to zero and you're glad you did it; or you get close, give up and it goes back to where it was before, in which case you wasted all that credibility, activity, money that could have been applied to other things.

In low-income countries, getting to a health post is hard. It's very expensive.

The most interesting biofuel efforts avoid using land that's expensive and has high opportunity costs. They do this by getting onto other types of land, or taking advantage of byproducts that aren't used in the food chain today, or by intercropping.

If I hadn't given my money away, I'd have had more than anyone else on the planet.

I think there will be PCs at every price point.

My mom was on the United Way group that decides how to allocate the money and looks at all the different charities and makes the very hard decisions about where that pool of funds is going to go.

Money has no utility to me beyond a certain point.

Well private money can take risks in a way that government money often isn't willing to.

We've got to put a lot of money into changing behavior.

Rich countries can afford to overpay for things.

Money has always been in politics. And I'm not sure you'd want money to be completely out of politics.

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.

Well-spent aid money is saving lives for a few thousand dollars per life saved.

I actually thought that it would be a little confusing during the same period of your life to be in one meeting when you're trying to make money, and then go to another meeting where you're giving it away. I mean is it gonna erode your ability, you know, to make money? Are you gonna somehow get confused about what you're trying to do?

While money can’t buy happiness, it certainly lets you choose your own form of misery.

Stop chasing the money and start chasing the passion.

The circulation of confidence is better than the circulation of money.