In the history of the world, no one has ever washed a rented car.

When I look out the window at my backyard, I can't think of anything interesting to ask. I mean, it's green, it's growing-but nothing occurs to me that any concentrated effort of thought could possibly enlighten. Whereas in economic, statistical, or mathematical kinds of things, I can think lots of questions.

What's the single most important thing to learn from an economics course today? What I tried to leave my students with is the view that the invisible hand is more powerful than the hidden hand. Things will happen in well-organized efforts without direction, controls, plans. That's the consensus among economists. That's the Hayek legacy.

The United States basically accepted protection abroad as the price of post-war recovery. Now, that these countries have caught up to our level of prosperity, it is time for them to catch up to our level of openness.

With uncertainty in oil markets, a buildup of speculative pressures and the large U.S. current account deficit, there is a real possibility that Paulson's crisis-management skills will be tested.

It used to be said that when the U.S. sneezed, the world caught a cold. The opposite is equally true today. Our prosperity is linked inextricably to the maintenance of a strong world economy, an open international trading system, and stable global financial markets.

The major challenge for the United States is whether it can become the first outward-looking, continental, nonimperialist power in history.