A collapse in U.S. stock prices certainly would cause a lot of white knuckles on Wall Street. But what effect would it have on the broader U.S. economy? If Wall Street crashes, does Main Street follow? Not necessarily.

Both humanity's capacity to innovate and the incentives to innovate are greater today than at any other time in history.

The lesson of history is that you do not get a sustained economic recovery as long as the financial system is in crisis.

Indeed, in general, healthy investment returns cannot be sustained in a weak economy, and of course it is difficult to save for retirement or other goals without the income from a job.

The crisis and recession have led to very low interest rates, it is true, but these events have also destroyed jobs, hamstrung economic growth and led to sharp declines in the values of many homes and businesses.

If your uniform isn't dirty, you haven't been in the game.

The amount of currency in circulation is not changing. The money supply is not changing in any significant way.