Tornado Alley (PROG)

[blackhawks]

Table Table44 presents the lagged effects of the Sturgis Rally on the natural log of COVID-19 cases. Our findings in Column (1) show that the highest relative inflow counties to Sturgis (outside of the state of South Dakota), which were comprised of counties representing states nationwide, including Arizona, California, Colorado, Iowa, Minnesota, Nebraska, Nevada Washington, and Wyoming 27 —saw a 10.7% increase in COVID-19 cases more than 3 weeks following the opening of the Sturgis Rally, and about 2 weeks following the close of the events.

Note that this effect is identified of each of these counties' own county-specific time trend relative to similar trends in noninflow counties. Over the same time window, we find that the second highest inflow counties (151 counties) also experienced about a 12.5% increase in COVID-19 cases following the events.

Turning to our “moderate inflow” counties (630 counties), we also see that a diverse set of counties from states across the nation also saw about a 7% increase in COVID-19 cases, beginning about 10 days following the official close of the Sturgis Rally. These effects are all significantly different from zero. This suggests that the COVID-19 spread effects of Sturgis occurred far more widely than just the state of South Dakota or its border states. It also suggests that the superspreading effects of the event were diffused across the nation. 28

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7753804/