Jeff Miron has a whole op-ed on the wonders of the undergraduate econ major. But I think I can put the case for the econ major more succinctly. Here goes: Econ is the highest-paid of all the easy majors.
My students often howl in protest when I say this, but come on: Econ does not put the crimp on your social life that CS or Engineering do. It's not even close.