Fig 3.

Event study analysis of city lockdown. These figures present the results of the parallel trend tests based on Eq. (4). The control group is the cities without lockdown. The last group of cities that declared the lockdown policies on February 13, 2020, are all located at Inner Mongolia, as our sample date ranges from January 1 to May 2, 2020. Forty-three days are remaining until they impose the lockdown, while there are 99 days left after Wuhan firstly imposed the lockdown policy on January 23, 2020, during the sample period