I've recently been challenged on my proposal that a reasonable way to estimate a student's future GPA is to look at his/her current GPA. I am looking for any papers that study the correlation of students' GPAs along their academic career. In particular, I'd like to know the correlation between first-year grades and second-year grades and if the correlation varies by subject.
I've found some documents that look to be internal-use (for example, these http://www.baylor.edu/irt/index.php?id=75588 from Baylor University), but nothing that has been peer-reviewed.