The U.S. economy is red hot, adding 517,000 jobs in January. Unemployment is at its lowest rate in more than 50 years. So why are there so many jobs when there's talk about a possible recession? One idea that's been talked about is labor hoarding, where employers hold onto more staff than they need. That's because the costs of rehiring are so high. We find that the answer is more complex — and maybe a little more optimistic as well.