One interesting way of thinking about time periods in American history is by looking at the extent to which government control (measured in the below chart as spending as a percent of GDP) of the economy is going up or down.
Source: USGovernmentSpending.com
In bull markets, government is getting more important in people’s lives. In bear markets, concerns about government are pushed to the side and markets thrive. Considering the entitlement spending shift has yet to hit, it is unlikely that we will be going back to bear market anytime soon.