Regression-Discontinuity Design - Institute for Policy Research

Implications for Practice
• Which approach to use?
– Use univariate approach first for estimating τ R and τ M and
to assess whether treatment effects are constant.
– If treatment effects are constant, use frontier or centering
approach for estimating τ MRD .
• Use frontier approach only if functional form of the response
surface is known
• For the centering approach, may reduce heterogeneity in the
outcome by using difference scores for the outcome
– The IV approach is not recommended because we do not
know when the potential outcomes are discontinuous and
because of reduced efficiency