Narrator: This is Science Today. Michael Hout is one of six University of California, Berkeley sociologists who've pinpointed how the gap between rich and poor has spread in the United States. Hout says one way to start spreading the wealth again is to get corporations to put down roots in towns and cities once more.

Hout: And one way we do that is by requiring them to invest in the community...

Narrator: Because that gives them economic incentive to stay. Hout says that right now, communities make it too easy for companies to come and go.

Hout: Corporations come into town, they're presented with an industrial park that they don't have to build and therefore they have no investment in. The tax break lasts five years, the plant lasts five years, the company's once again up and on the move as soon as the five year lease is up. If companies have to put something back into the community, they're invested in that community, they're tied to that community, they don't up and leave. We can't always rely on the beneficent capitalist to pour conscience money into the community, we have to give them incentives to stay.

Narrator: For Science Today, I'm Steve Tokar.