Matchmaking. La scienza economica del dare a ciascuno il suo (or here or here)
(Matchmaking. The economics of giving to each his own).
I guess that's a pretty good way to translate Who Gets What and Why.
Nico Lacetera writes: "I like the subtitle "a ciascuno il suo", which refers to a latin way of saying (suum cuique ~ to each, their own) -- in turn, this is the title of a famous novel by a major Italian contemporary writer, Leonardo Sciascia."