Each worker maximizes U=W - K/IQ, where W is the worker's wage, K is a constant, and IQ is the worker's IQ. K/IQ is a signaling cost; the smarter you are, the less painful you find it to get your diploma. (A???0 because this signaling cost function would not make sense with negative A).Given the set-up, there is clearly going to be an IQ level such that everyone above it gets a diploma and everyone