Certainly, 9 percent unemployment and very slow growth is not a good situation.

Growth in U.S. real imports slowed to about 3 percent in 2006, in part reflecting a drop in real terms in imports of crude oil and petroleum products.

The destruction wrought by Katrina and Rita may reduce growth somewhat in the short run, but the longer-term growth trajectory remains in place.

If Australia finds it has a strong Australian dollar, and it has higher unemployment, then it would have to respond, and that would either be by increasing domestic demand or by weakening its own currency.

Textbooks describe economics as the study of the allocation of scarce resources. That definition may be the 'what,' but it certainly is not the 'why.'

A collapse in U.S. stock prices certainly would cause a lot of white knuckles on Wall Street.