Page 16 of our article [Brodeur et al., 2021] contains an error in the back-of-the-envelope calculations of the positive pollution and collision externalities generated by safer-at-home orders. We are very grateful to Tom Bohlken of the University of Oldenburg for bringing this error to our attention.
In estimating the monetary benefits of reduced traffic collisions from safer-at-home orders, the original study does not account for the observed number of collisions. The net reduction in collisions is approximately 1.77 counterfactual collisions per county-day minus 1.4 observed collisions per county-day. Using the original study's valuation of 72,732 USD per crash for the 124,370 county-days of stay-at-home orders during the sample period, this represents a net positive benefit of 3.3 billion USD. Our estimates of the positive externalities of reduced air pollution are not affected.