Now Playing: 12-09-13 Marketplace - Sysco. Not Cisco.

That steak on your plate? Those mashed potatoes? Them tender greens? Chances are they came to you courtesy of one of America’s food distribution behemoths. The biggest of the bunch, Sysco, is buying U.S. Foods in the biggest food distribution deal in a decade. Plus, the battle over EPA rules for Midwestern and Appalachian air polluters comes down to what economics calls externalities. It all comes down to this question: Pollution isn’t free … but who should pay? And finally, as more people are excluded from homeownership, the demand for rental housing has grown beyond capacity, driving rental costs up.