http://files.eric.ed.gov/fulltext/ED502858.pdf – Among 80k UC students, the following regression coefficients best predicted graduation rate. I listed the average across the 4 cohort groups for the 4 sample years. With similar UC GPA and similar SES, the model predicts the student with the lower SAT M+V score student has a slightly better chance of graduating. For 4th year GPA, a model without SAT M+V explains 26.3% of variance in college GPA. A model with SAT M+V explains 26.5% of variance… essentially no change.
SAT I Verbal: -0.03
SAT I Math: -0.01
SAT II Math: -0.03
http://www.heri.ucla.edu/DARCU/CompletingCollege2011.pdf – With a full model that includes academic characteristics, SES/financial characteristics, major/college characteristics, and time spent on various activities during HS they could explain 26.9% of variance in 6-year grad rate with 71.4% successful predictions. When they excluded test scores from the model, the prediction dropped by only 0.1% from explaining 26.9% of variance to explaining 26.8% of variance, with both successfully predicting graduating for 71.4% of students… essentially no difference.
http://www.ithaca.edu/ir/docs/testoptionalpaper.pdf i-- when using a model that considered HS GPA, HS rank, strength of HS schedule, AP credit hours, gender, race, and first gen; they could explain 43% of variance in GPA at Ithaca. When they also considered SAT scores in the model, the prediction accuracy increased by only 1% from 43% to 44%, with only the SAT writing section being statistically significant in improving prediction beyond the other sections of the model.
http://www.aera.net/Newsroom/RecentAERAResearch/CollegeSelectivityandDegreeCompletion/tabid/15605/Default.aspx
“The ATT indicates that there could be a small SAT effect on graduation (2.2 percentage points for a standard deviation increase in college SAT), but this does not reach statistical significance. The ATU is much smaller in magnitude and is not significantly different from zero.”
I could list more, but the point is every study I have ever seen that controls for both a measure of HS GPA and a measure HS course rigor came to a similar conclusion about the additional benefit of SAT I beyond the controls.