How Wasteful is Signaling?

Signaling is wasteful. But how wasteful? We study the fraction of surplus dissipated in a separating equilibrium. For isoelastic environments, this waste ratio has a simple formula: $\beta/(\beta+\sigma)$, where $\beta$ is the benefit elasticity (reward to higher perception) and $\sigma$ is the elasticity of higher types' relative cost advantage. The ratio is constant across types and independent of other parameters, including convexity of cost in the signal. A constant waste ratio characterizes the isoelastic class. In winner-take-all signaling tournaments with $N$ candidates, exactly $(N-1)/N$ of the surplus dissipates -- the same as in Tullock contests.