From the 16th edition of the (University of) Chicago Manual of Style:
6.21 Omitting serial commas before ampersands. When an ampersand is used instead of the word and (as in company names), the serial comma is omitted.
In a world in which the legendary fistfight between Jack Kerouac and William S. Burroughs over the Oxford comma was recently exposed as apocryphal—a polite way of saying nothing remotely like it ever happened—there are those who might wonder if punctuation is actually the cornerstone of civilization it's made out to be. Well, the world can afford your skepticism, and possibly even my own. But to see the U. of C. go willy-nilly is to despair.