Random assignment is insufficient for measured treatment responses to recover causal effects (comparative statics) in dynamic economies. We characterize analytically bias probabilities and magnitudes. If the policy variable is binary there is attenuation bias. With more than two policy states,...

Causal evidence from random assignment has been labeled "the most credible." We argue itis generally incomplete in finance/economics, omitting central parts of the true empirical causalchain. Random assignment, in eliminating self-selection, simultaneously precludes signaling viatreatment...

Random assignment is insufficient for measured treatment responses to recover causal effects (comparative statics) in dynamic economies. We characterize analytically bias probabilities and magnitudes. If the policy variable is binary there is attenuation bias. With more than two policy states,...