State mandates that promote physical distancing—especially limits on bars and restaurants—do cut the amount of time people spend away from home, according to a new study.
Social distancing (or “physical distancing”) mandates have been the main way that state and city governments are curbing the spread of the novel coronavirus.
But how much do declaring states of emergency, implementing stay-at-home orders, shuttering non-essential businesses, and other policies and guidelines actually keep people from moving around and coming into contact with each other?
“The limits on bars and restaurants seems to be the single policy that was associated with the greatest reduction of population mobility.”
“When the COVID-19 pandemic started, it was really a natural fit for our team to start brainstorming ideas about how Google could contribute meaningful insights to help guide the global public health response to the pandemic,” says Gregory Wellenius, a researcher at the Boston University’s School of Public Health who collaborated on the work with Google as part of its COVID-19 Community Mobility Reports project.
Wellenius began a short-term position as a visiting scientist at Google Research in January. Much of his research uses new technologies and data sources to better understand and address the harms of climate change.
The team soon launched the COVID-19 Community Mobility Reports and began using the data for research, looking for insights that could be useful to the pandemic response.
The study finds that state-of-emergency declarations resulted in a 10% reduction in time spent away from places of residence. The implementation of one or more physical distancing policies resulted in an additional 25% reduction (and a 33% reduction in visits to retail and recreational locations), and subsequent shelter-in-place mandates led to an additional 29% reduction in the time that people spent out and about.
“The limits on bars and restaurants seems to be the single policy that was associated with the greatest reduction of population mobility,” says Wellenius, director of SPH’s Program on Climate and Health.
However, he notes that states with a combination of orders saw the biggest reductions in how much time people spent away from their places of residence and moved around, where they could potentially contract or transmit the coronavirus. The report also revealed that, compared to baseline data from before the pandemic, people were spending significantly more time in parks.
The reports use anonymized data (and cutting-edge differential privacy measures, which Wellenius and colleagues outlined in another recent paper) from users that have opted in to this service, in much the same way that Google Maps shows how busy a particular location is. The Community Mobility Reports use these anonymized data to map trends in how the COVID-19 pandemic—and state-level policies to control it—are affecting where people are spending more or less time.
The new paper is the first of several that may come out of the project, Wellenius says.
“A reasonable question for a local official or governor to ask is, ‘Which of these policies, or combination of policies, will give us the results that are best suited to the pandemic here, and the economy here, and the public health here in my state?'” Wellenius says. He and his Community Mobility Reports collaborators are now working to provide more location-tailored information to help answer those questions.
The paper is available as a preprint on arXiv.
Source: Boston University