Abstract This paper reports the results of a Monte Carlo simulation study, which accompanies Marmer, Feir, and Lemieux, "Weak Identification in Fuzzy Regression Discontinuity Designs".

In fuzzy regression discontinuity (FRD) designs, the treatment effect is identified through a discontinuity in the conditional probability of treatment assignment. We show that when identification is weak (i.e. when the discontinuity is of a small magnitude) the usual t-test based on the FRD...