retirement-assets tied up in large part in unstable Internet stock.

As they feel less secure, Mankiw says, people might choose to eat out a little less often and wait before purchasing durable goods, like a new house, car or even a new set of silverware.

"They'll start deciding to eat macaroni and cheese a few times instead of going out to dinner," he says.

He predicts, then, that the current economic slowdown would have the most visible effect on a store like Crate & Barrel, or on costly Square restaurants.

"People might be nervous and decide to put off buying that new dining room table," Mankiw says. "The more durable the good, the more volatile the business cycle."

But at Crate & Barrel, manager Josh Murphy says sales are level since last year.

The store has not changed any hiring practices or been forced to mark down prices.

As he talks, customers browse through the three floors of home decorations-from colorful arrays of plates and cups to couches, chairs and tables.