Indiana University researchers have released results from the first comprehensive study of how COVID-19 mitigation policies affect measures of individual movement and contact in the United States. The results indicate that government mandates that happened late in the sequence of events like stay-at-home orders have very little impact on voluntary quarantine compared to early state actions of a more informational nature such as emergency declarations, and other state and local news.
The researchers used publicly provided near-real-time cell signal data from more than 20 million devices per day to measure time spent at home, social mixing and traveling. They collected and developed a classification system of state and county-level policy responses, as well as information events relevant to the epidemic, such as announcements about the first positive case of COVID-19 in an area or the first reported death from the virus.
"While government actions such as stay-at-home orders happened after much of the public's movement had already slowed and may not have had a great influence, that doesn't mean that lifting those quarantine policies will not have an impact on mobility now," said Ana I. Bento, assistant professor in the Department of Epidemiology and Biostatistics at the IU School of Public Health-Bloomington. "The prevailing national attitude and news of cases are just as influential, our research finds."