How Long Will Social Distancing Last? UCR Professor's Answer

RIVERSIDE COUNTY, CA — Interventionist strategies for containing the novel coronavirus should involve quarantines, mass testing and related measures for 45 days, or at least three weeks, to put the brakes on viral propagation, according to a newly released study co-authored by a UC Riverside professor.

In a thesis titled "How Long Must Social Distancing Last?," UCR Anderson School of Business Professor Ashish Sood, along with USC Marshall School of Business Professor Gerard Tellis and Augusta University molecular biology researcher Nitish Sood, reviewed how the 50 U.S. states and 36 countries were managing COVID-19 mitigation.

Based on their analysis, they derived specific metrics to monitor — daily growth rate, and time to double cumulative cases of the virus.

The growth rate refers to a percentage increase in COVID-19 cases daily, while the doubling time represents the number of days for caseloads to double, according to the researchers.

"These simple, intuitive and universal benchmarks give public health officials clear goals to target in managing this pandemic," Sood said. "Singapore and South Korea adopted the path of massive test and quarantine, which seems to be the only successful alternative to costly lockdowns and stay- at-home orders."

The professor and his counterparts emphasized that the benchmarks which public health authorities should follow are "moderation," which occurs when the growth rate slows to below 10 percent and the doubling time is more than seven days; "control," when the growth rate remains below 1 percent and the doubling time is above 70 days; and "containment," when the rate holds at or below a 10th of a percent and the doubling time is over 700 days.

"Even though huge differences exist among countries, it's striking to see so many similarities, from aggressive intervention to moderation, control and containment of the spread of the disease," Sood said.

The researchers said Singapore's and South Korea's aggressive tactics were netting positive results.

"Besides size of country, borders, cultural greetings — bowing versus handshaking and kissing — temperature, humidity and latitude may explain differences (between nations' successes in containment)," Tellis said.

When aggressive strategies are utilized, moderation in large countries typically materializes in three weeks, with about 30 days for control and 45 days for containment, according to the researchers.

The thesis further highlighted the need for new medicines and technologies to combat COVID-19. The paper also mentioned that innovations as yet unidentified could be the key to stopping it.

The researchers said California's stay-at-home and social distancing requirements fall into the "aggressive" category, and they conceded that there are limits to how far the federal and state governments may go in the face of civil rights constraints provided by the U.S. Constitution.

The study can be read in full at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3562996.