I am trying to predict first term GPA for college students based on a number of incoming factors (high school gpa, placement test, year). This isn't the overall model just a simpler one. The first term GPAs are on the interval 0 to 4, however the predictions from the linear OLS model (i'm using sklearn) never go above 3.6 (see picture). Is this some sort of gotcha that I am missing? There are certainly data in the training set with first term GPA that is between 3.6 and 4.0. I didn't expect perfect performance but this is odd to me.