(NBC News) — The Sturgis Motorcycle Rally held in South Dakota last month may have caused more than 250,000 new coronavirus cases, according to an economic study focused on the public health costs of “superspreading” events.
The 10-day rally attracted more than 400,000 people. Prolonged interactions between individuals at high frequencies, along with “minimal mask-wearing and social distancing by attendees,” raised concerns that Sturgis would lead to increased transmission of coronavirus, according to a new study from the IZA Institute of Labor Economics.
A synthetic control approach conducted by the researchers estimated the number of cases to 266,796 or 19 percent, the study said.
The nonprofit company’s findings have not been corroborated by epidemiologists or public health officials.