University of Iowa researchers provide empirical data and analysis showing that stay-at-home orders may reduce the rate of coronavirus.
Wei Lyu and Dr. George Wehby studied covid-19 spread in the Mississippi River border counties of Illinois and Iowa. In mid-March, Illinois’s western border counties had a cumulative coronavirus cases rate of 0.026 per 10,000 people; Iowa’s eastern border counties had a case rate of 0.024 per 10,000. Illinois implemented a stay-at-home order on March 21; Iowa issued a variety of business and school closure orders from March 17 through April 6 but never a stay-at-home order. What happened to coronavirus rates?
Trends were comparable before the Illinois stay-at-home order became effective…. After that, cases increased more quickly in Iowa. The difference-in-differences regression estimates also indicated a slower increase in COVID-19 cases in Illinois…. Within 10, 20, and 30 days after the enactment of the stay-at home order in Illinois, the difference in cases was −0.51 per 10 000 residents…, −1.15 per 10 000 residents…, and −4.71 per 10 000 residents…, respectively. The estimates indicate excess cases in the border Iowa counties by as many as 217 after 1 month without a stay-at-home order. This estimate of excess cases represents 30.4% of the 716 total cases in those Iowa counties by that date [Wei Lyu and George L. Wehby, “Comparison of Estimated rates of Coronavirus Disease 2019 (COVID-19) in Border Counties in Iowa Without a Stay-at-Home Order and Border Counties in Illinois with a Stay-at-Home Order,” JAMA Network Open, 2020.05.15..
Lyu and Wehby note that Iowa Governor Kim Reynolds said that her lighter measures were “equivalent” to other states’ stay-at-home orders:
Reynolds said that guidance is “equivalent” to the orders that other states, such as neighboring Illinois, are taking. She is confident that Iowans following those guidelines will be key in making sure the novel coronavirus’ spread is stunted and Iowa’s health care facilities aren’t overrun.
“What else are we doing by doing (a shelter-in-place or stay-at-home order) except for potentially disrupting the supply chain, putting additional pressure on the essential workforce, and making sure that we are considering how we bring that back up?” Reynolds said. “And, actually, what’s the benefit of taking that additional step?” [Nick Coltrain, “Gov. Kim Reynolds: Iowa Is Already Under ‘Equivalent’ of Stay-at-Home Order to Fight Coronavirus,” Des Moines Register, 2020.03.25]
The benefit, suggest Lyu and Wehby, maybe be 30% fewer cases of coronavirus.
No practical policy will eliminate coroanvirus right here, right now. And Illinois still has plenty of coronavirus cases. But reducing the spread of a potentially deadly disease by 30% shows that stay-at-home orders make sense as part of a comprehensive public policy response to a pandemic.