Seven reasons to expect a slow-growth U.S. economy ahead

Is the U.S. headed for a "new normal" -- a slow-growth economy that lasts perhaps for as long as a decade? The evidence supporting the new-normal argument, predicting a future in which the U.S. GDP grows at no more than 2.0% to 2.5% per year, is compelling. That low growth rate would constrain corporate revenue, earnings growth and stock prices, among other consequences.

The U.S. has already registered below-trend GDP growth at this recovery's start -- just 3.5% in the third quarter, versus the more than 6% GDP growth typically registered in an expansion's initial stage. Here's why the slow-growth conditions might continue: