only marginally significantp < 0.10
There is weak evidence of a violation of the common trends assumption in Missouri for visits per 10,000 beneficiaries, but the coefficient on the linear time trend in Missouri is only marginally significant ( p < 0.10). 5.3 Robustness checks To examine the robustness of the cohort and quarter specific ATTs from the Wooldridge ( 2021 ) estimator, we also estimated a specification using the Callaway and Sant’Anna ( 2021 ) difference‐in‐differences estimator using doubly robust estimation as specified in Callaway and Sant’Anna ( 2021 ) and Sant’Anna and Zhao ( 2020 ).