FEDS Paper: Discussion of “Dynamic Causal Effects in a Nonlinear World: the Good, the Bad, and the Ugly”

Edward P. Herbst and Benjamin K. JohannsenThis comment discusses Kolesár and Plagborg-Møller's (2025) finding that the standard linear local projection (LP) estimator recovers the average marginal effect (AME) even in nonlinear settings. We apply and discuss a subset their results using a simple nonlinear time series model, emphasizing the role of the weighting function and the impact of nonlinearities on small-sample properties.