[…] A common question on discussion forums is how to compute a principal component regression in SAS. One reason people give for wanting to run a principal component regression is that the explanatory variables in the model are highly correlated which each other, a condition known as multicollinearity. Although principal component regression (PCR) is a popular technique for dealing with almost collinear data, PCR is not a cure-all. This article shows how to compute a principal component regression in SAS; a subsequent article discusses the problems with PCR and presents alternative techniques. …