Google data shows effect of COVID-19 social distancing policies
For much of 2020, states and municipalities have used various social distancing policies in hopes of keeping rates of COVID-19 infections down. These have ranged from emergency declarations to official stay-at-home orders. While the assumption that people who remain home more often are less likely to spread infection or get infected themselves, up until recently there was little data to show just how effective these measures can be.
A new report by Boston University School of Public Health (BUSPH) researcher, Gregory Wellenius, conducted in collaboration with Google and available via preprint on arXiv, shows that state-level social distancing policies substantially reduced the number of trips people made to retail establishments, restaurants, parks, and to work. Overall, social-distancing policies reduced the time people spent away from their homes by about 25%. Interestingly, even the initial declaration of a state of emergency led to about a 10% decrease in the amount of time people spent away from their homes, even though emergency declarations don’t typically explicitly ask people to stay home.
More stringent shelter-in-place mandates reduced the amount of time people spent away from their homes by 29%.. “In the absence of a shelter-in-place order, 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 The Program on Climate and Health at BUSPH and a visiting scientist at Google throughout 2020.
And when people stayed home more, there were fewer cases of COVID-19 in the subsequent few weeks. For example, a 10% reduction in population mobility was associated with a 17.5% reduction in COVID-19 case growth 2 weeks later.
“These results show that social distancing policies are effective at encouraging people to stay home and reducing case counts in the next few weeks.” says Wellenius
The COVID-19 Community Mobility Reports project
The research leverages data provided by Google’s COVID-19 Community Mobility Report, which uses aggregated, anonymized insights they use in products such as Google Maps to help public health officials make critical decisions to combat COVID-19.
“Google has a tremendous amount of expertise, computational power, and data; and the question is really, how can we use that to help the world deal with the COVID-19 pandemic while protecting user privacy and anonymity,” said Wellenius.
The project first looked at providing timely information about how people were moving during the pandemic, which led to Wellenius and Google then researching how social distancing—also known as physical distancing—policies in the U.S. are impacting people’s behavior and rates of infection. For example, the report revealed that, compared to baseline data from before the pandemic, people are spending significantly more time in parks.
Research can inform COVID-19 policies
Armed with this publicly-available information, state public health officials, as well as state and local elected officials, can make more data-driven decisions about which policy or which combination of policies will be the most effective in reducing transmission while also balancing the economic implications of these orders. Wellenius also collaborated on a similar analysis considering the effectiveness of India’s national lockdown at the start of the pandemic.
Opportunities for continued research on COVID-19 public health policies and physical distancing can further shed light on how these policies are being followed, and what long-term impact they may have on populations’ mobility. This research, similar to the work being done by Wellenius, is one of the many projects that idea hub can facilitate with corporate collaborators.
Wellenius, the director of The Program on Climate and Health at BUSPH, began his work with Google in January 2020, as a visiting scientist at Google Research. His role there was initially focused on public and environmental health.
“I was working on this team at Google that was focused on public and environmental health 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,” said Wellenius.
Wellenius will continue to work with Google researchers on the key issue of how environmental factors, particularly climate change, impacts our health. For more information about collaborating on similar COVID-19 related research, talk to us at idea hub.