Figure 1.

Ratio of the mean estimated standard error to the standard deviation of the estimates of ${\tau }_{31}$ for the correct parametric implementation according to sample size (dark gray = 500, gray = 1000, light gray = 2000), the strength of the association between covariates and treatment (columns; weak= $T-$ or strong= $T+$) and between the covariates and outcome (weak= $Y-$ or strong= $Y+$), and implementation (rows; Cor = Correct parametric, Inc = Incorrect parametric, ML = machine learning).