The study, released today by the National Bureau of Economic Research, examines the college grades of students admitted to the University of Texas at Austin through the "10 percent program" in which the top students at every Texas high school have been guaranteed admission (although the percentage has been reduced somewhat since the plan was created).

The study (abstract available here) found that the quality of high school is a key predictor of grades in college, not only in freshman year, but continuing into the sophomore and junior years as well.