From Farrington & Tarling’s Prediction in Criminology, a new term: predictive efficiency. The way to think about it is this — suppose I say that a college education predicts low incidence of being convicted of a violent crime, and at the end of the day I’m right — over the course of a year, 97.5% of our college grads are not convicted.

In the absence of a base rate, that doesn’t really tell us anything. It can be a good predictor in that it does predict at high rates of certainty, but it’s inefficient compared to alternative predictors.