Thomas Friedman has a lucid commentary on the causes of the current financial crisis in today's NYT: Why How Matters

A quote which well summarizes his argument:

You cannot tell tens of thousands of people that they can have the American dream a home, for no money down and nothing to pay for two years without that eventually catching up to you. The Puritan ethic of hard work and saving still matters.

I don't always agree with the NYT (see here), but she's still got some good things to say, especially when Tom Friedman's the one saying them.