A surprisingly optimistic outlook among younger Americans and a higher stock market pushed up a measure of U.S. consumer sentiment in February.

The increase was small, but the harsh winter weather appears to have had little effect on Americans' confidence so far. That's a sign that spending might pick up in the coming months. The University of Michigan's consumer sentiment index ticked up to 81.6 in February from 81.2 in January. It's still slightly below December's figure. The survey also found that Americans under age 35 have grown more optimistic that their pay will increase. On average, they expect income gains of 5 percent over the next 12 months, the survey found.

That's the largest expected gain since November 2006.