Table 2.

Weighted and centered estimator of the marginal proximal treatment effect, β̂₁, using two choices for p̃_t.

p̃t	Mean	SD	RMSE	CP
Constant in t (i)	−0.20	0.08	0.08	0.94
Depends on St (ii)	−0.14	0.09	0.11	0.89

RMSE, root mean squared error and SD, standard deviation of β̂₁; CP, 95% confidence interval coverage probability for ${\beta }_1^{\ast }=-0.2$. Results are based on 1000 replicates with n = T = 30. Boldface indicates whether Mean or CP are significantly different, at the 5% level, from −0.2 or 0.95, respectively.