If you can get good at destroying your own wrong ideas, that is a great gift.

How should the best parts of psychology and economics interrelate in an enlightened economist's mind?... I think that these behavioral economics...or economists are probably the ones that are bending them in the correct direction. I don't think it's going to be that hard to bend economics a little to accommodate what's right in psychology.

There are two kinds of businesses: The first earns 12%, and you can take it out at the end of the year. The second earns 12%, but all the excess cash must be reinvested - there's never any cash. It reminds me of the guy who looks at all of his equipment and says, 'There's all of my profit.' We hate that kind of business.

Berkshire's whole record has been achieved without paying one ounce of attention to the efficient market theory in its hard form. And not one ounce of attention to the descendants of that idea, which came out of academic economics and went into corporate finance and morphed into such obscenities as the capital asset pricing model, which we also paid no attention to. I think you'd have to believe in the tooth fairy to believe that you could easily outperform the market by seven-percentage points per annum just by investing in high volatility stocks.

For many of our shareholders, our stock is all they own, and we're acutely aware of that. Our culture [of conservatism] runs pretty deep.

In the 1930s, there was a stretch where you could borrow more against the real estate than you could sell it for. I think that's what's going on in today's private-equity world.

Another thing I think should be avoided is extremely intense ideology because it cabbages up one's mind. You see it a lot with T.V. preachers (many have minds made of cabbage) but it can also happen with political ideology. When you're young it's easy to drift into loyalties and when you announce that you're a loyal member and you start shouting the orthodox ideology out, what you're doing is pounding it in, pounding it in, and you're gradually ruining your mind. So you want to be very, very careful of this ideology. It's a big danger.