Fig. 2
Contour plot for the percent increase in bias across a range of parameters for the slope of the treatment effect. The x-axis displays values for the measurement error parameter for the change in slope for the control group (γ3), the y-axis displays values for the measurement error parameter for the change in slope for the treatment group (λ4). Increases in differential measurement error with respect to treatment have a stronger impact on bias than do increases in differential measurement error with respect to time