The preliminary growth reading for the fourth quarter was barely over zero. When the gross domestic product result is updated this week, economist and investment strategist Ed Yardeni isn't ruling out a dip into negativity. From his note to clients this morning:

This week, we’ll get to see if a recession started during Q4-2007. The quarter’s revised growth rate will be reported on Thursday. The preliminary number was up 0.6%. It wouldn’t take much to push this number into negative territory. However, the Bloomberg consensus of economists is a slight upward revision to 0.7%. The economists at Macroeconomic Advisors, who track real GDP on a monthly basis, are expecting no change from the preliminary number.