We're now at the tail end of a very long, but in many ways a very weak and artificial, economic expansion. At the same time we've had one of the strongest securities bull markets in history. Both are the result of trillions of new dollars created over the last decade. Right now very few people are willing to consider the possibility of tough times—let alone The Greater Depression.

But, perverse though it may seem, this is the very best time to think about it. The U.S. economy is a house of cards, built on quicksand, with a tsunami on the way. I urge everyone to read up on the topic. For now, I'll only briefly touch on the nature of depressions. There are at least three good definitions of the term:

A period of time when most people's standard of living drops significantly.

A period of time when distortions and misallocations of capital are liquidated.

A period of time when the business cycle climaxes.