Sequential IgnorabilityΒΆ
Assumption - No unmeasured confounding given observed history.
Applies to - IS, WIS, PDIS, DR, WDR, MAGIC, MRDR, MIS, FQE, DualDICE/GenDICE, DRL, HCOPE, Double RL.
Definition - Conditional on observed history, the action at each time step is independent of potential outcomes under alternative actions.
Diagnostics - Not directly testable; use domain knowledge and falsification tests.
Failure modes - Hidden confounding yields biased OPE estimates.
References - Hernan and Robins, Causal Inference: What If.