From Forbes:

In a certain way, the U.S. is about to find out what the 1980s economy would have been like without the tax cuts enacted by President Reagan. The last time the jobless rate spiked to 10% and higher was during the brutal recessions of 1981-82. If high unemployment is a reason not to invest today, it was an even bigger reason not to invest back then. But staying out of the market--remaining pessimistic because of high unemployment--meant you missed out on at least a part of the bull market.

Back in the early 1980s, President Reagan cut marginal tax rates across the board and, at least for a few years, restrained the growth of government social spending. Now we have similar 10% unemployment and public policy is moving in the exact opposite direction, with higher taxes and bigger government.