At a Ford plant in Michigan, workers load a battery into a Ford C-MAX plug-in hybrid vehicle. The economy picked up speed in the third quarter. Economists caution, though, that it may slow in coming quarters. Bill Pugliano/Getty Images hide caption

itoggle caption Bill Pugliano/Getty Images

Shoppers came out in the first quarter, pushing up economic growth. Robyn Beck /AFP/Getty Images hide caption

itoggle caption Robyn Beck /AFP/Getty Images