A well-known property of regression models is that they capture the unique contribution of a predictor. By “unique” we mean the effect of the predictor (on the criterion) if the other predictor(s) is/are held constant. A typical classroom example goes along the following lines. All about storks There’s a correlation between babies and storks. Counties with lots of storks enjoy large number of babies and v.v. However, I have children, I know the storks are not overly involved in that business, so says the teacher (polite laughters in the …