Figure 2.

Bias of using $\widehat{\Delta }\left(I\right)$ to estimate Δ as a function of covariate correlation, based on the first simulation study. Each panel displays results for estimates with different model mis-specifications: correct propensity and response models (squares), correct propensity model and incorrect response model (circle), incorrect propensity model and correct response model (triangle), and incorrect propensity and response models (crosses).