The 'cash for clunkers' program was a big success in part because it gave people the sense that the economy was moving.

I'm interested in how the Internet spreads information.

If you have a regulation that's going to save hundreds of thousands of lives annually and not cost very much, that sounds like a very good idea.

Most problems are best solved privately, not through government. There's a problem of discourtesy in the world, which is best handled through social norms, which are indispensable. But you wouldn't want the government to be mandating courtesy.

I think President Barack Obama has been an extraordinarily successful president, and that this period will record that with a bunch of exclamation points. But obviously not everybody thinks that.

A program that saves young people produces more welfare than one that saves old people.

Groups become more extreme and entrenched in their beliefs and polarized from others when members only exchange information that reinforces their views and filter out all else or never learn of alternatives. Thus they narrow their options, and magnify each other's prejudices and misconceptions. This trend leads to blind spots in decision making and to extreme behavior, even terrorism.