make no difference. However, the small sample properties can differ. We explore small sample power and estimation bias both …) in the auxiliary model. We find that both power and bias are similar when the number of variables used is the same …. Raising the number of variables lowers the bias but may also raise the power unacceptably because it lowers the chances of …

We characterize the bias of propensity score based estimators of common average treatment effect parameters in the case …

We characterize the bias of propensity score based estimators of common average treatment effect parameters in the case …

We characterize the bias of propensity score based estimators of common average treatment effect parameters in the case … situations, even when selection is only on observables. -- Treatment effects ; propensity score ; bias ; unconfoundedness …

-hacking or publication bias, in particular for studies using an IV or DID approach. We show that a crucial continuity assumption …