Does Supplemental Instruction for Principles of Economics improve outcomes for traditionally underrepresented minorities?

Principles of Economics typically have a high non-success rate and traditionally underrepresented minorities (URMs) generally have a higher non-success rate than non-URMs. This paper describes our Supplemental Instruction (SI) course and tests the effectiveness of SI on grade improvement, while accounting for self-selection bias. We find that SI improves grades by a bit less than half a letter grade in the full sample and by a larger amount for URMs and a smaller amount for non-URMs. We also find evidence that weaker URM students and stronger non-URM students are more likely to enroll in our SI course.