Bill Gates, one of the world’s richest people, has given away $50 billion of his fortune. He talked with Andrew Ross Sorkin about politics, the Bill & Melinda Gates Foundation, family and his friendship with Warren Buffett in a wide-ranging conversation. This report has been edited and condensed.

There has been a question about the idea that vast fortunes in this country are able to be moved from the private sector into a foundation without paying tax. So the shares of Microsoft that you were able to generate, the shares that Warren Buffett was able to generate, there’s no capital gains on that, there’s no step-up on that. And so the U.S. taxpayer — the U.S. citizen — it’s not clear that they are beneficiaries of your success, to the extent you believe that they should be. What do you think of that? Would you ever be in favor of taxing philanthropy in that way of some sort?

We can raise taxes in a lot of ways, including, you know, making some gifts to foundations more taxed. We have a lot of room. The current thinking is not either in terms of encouraging philanthropy or discouraging and forming new business. We’re not close to the limit ... And it is important to separate out the question of should rich people pay more in taxes. The answer is yes.

For whatever remainder of money they have left over, I do think philanthropy is a good thing. I think it plays — that 2 percent of the economy — plays a role that neither the private sector nor the government are able to do in terms of various innovative approaches to, say, malaria, or nutrition, or trying out new models of education through things like charter schools.