“…If we substitute the counterfactual survival indicators S k , g =( R̄ m , 0 ) = 1 − R k , g =( R̄ m , 0 ) and S k , g =( R̄ m −1 , 0 ) = 1 − R k , g =( R̄ m −1 , 0 ) for R k , g =( R̄ m , 0 ) and S k , g =( R̄ m −1 , 0 ) in Eq (1), we obtain the structural nested multiplicative survival time model (SNMSTM) considered by Martinussen et al (2011, p. 776). We chose to fit an SNCFTM rather than a SNMSTM because, with rare failures, unconstrained estimation of an SNMSTM may result in estimated survival probabilities exceeding 1.…”