Gifted and talented programs provide extra services for academically high-performing students. Eligibility for these programs is typically based on having a test score above a threshold. A study by Bui, Craig, and Imberman (2014) estimate the effect on achievement of participating in a gifted and talented program using a regression discontinuity design.

a. Explain in words how the regression discontinuity method leads to a valid estimate of the causal effect of being in a gifted and talented program on educational outcomes.

b. Can this method tell us how very high-achieving students are affected by the gifted and talented program?

c. Would it be a problem for this approach if not all students who were eligible for the program decided to enroll in it?