Pandemic Politics: Timing State-Level Social Distancing Responses to COVID-19

Christopher Adolph; Kenya Amano; Bree Bang-Jensen; Nancy Fullman; John Wilkerson

We study state social distancing measures enacted over the period from the first reported case of transmission in the US on 26 February 2020 up through 23 March 2020, at which point all states had at least one social distancing policy. 1 To capture variation in these policies across states over time, we draw on data compiled by the National Governors' Association (NGA), which we verified and further documented by collect- 1 We consider the first community transmission in the US more epidemiologically and politically relevant than initial reported transmission in each state. At the time of first community transmission in the US, virologists including Trevor Bedford suggested this strain had been circulating in Washington state since mid-January. (19) Given scarce and unreliable testing, governors faced a choice to either take immediate action as national cases increased or wait for (potentially belated) reports of in-state cases. We prefer to treat the decision to wait for a confirmed case as something to be explained, and so control for confirmed in-state cases in our model.