By Michiel Bakker, Alex Berke, Matt Groh, Alex ‘Sandy’ Pentland, and Esteban Moro
What anonymous geolocation data can tell us about the effectiveness of social distancing policies
In response to the COVID-19 pandemic, social distancing policies have been issued across the world to reduce the immediate strain on the healthcare system and delay the spread of the virus such that the the healthcare system can better prepare. As of writing on March 29, 2020, New York City has 52,318 confirmed COVID-19 cases and 728 associated deaths. We looked at anonymous geolocation data from smartphones to answer how well social distancing policy is working in the New York City metropolitan area.
How well are people social distancing?
We prepared a report to answer the following three questions: (1) how has social distancing policy changed mobility and social behavior, (2) how does social distancing behavior vary across the physical space of New York City, and (3) how does social distancing behavior vary across demographic groups. We have summarized the main findings below, and you can read the initial draft of the report here.
- Social distancing policies in the New York City metropolitan area have resulted in empirically verified, dramatic changes in where people spend their time and with how many people they interact. For example, here are three striking differences between the weekends of late February and last weekend (March 20th) that we discovered when analyzing anonymized geolocation data in New York City:
~Distance travelled everyday dropped by 70 percent from a weekend average of 25 miles in February to 7 miles last weekend.
~The number of social contacts in places decreased by 93% from 75 to 5.
~The number of people staying home the whole day has increased from 20% to 60%.
- Supermarkets and grocery stores have become the most common place where social contact takes place.
- The national emergency declaration and school closure announcement on March 14th resulted in a huge surge of visits (up to 60% more) to many places. Most of this surge in activity happened at Grocery, Shopping, Food and Outdoor places. The reduction in distance travelled and daily social contacts became significant only after non-essential business closure measures were introduced on March 22nd.
- After the measures were introduced surges of activity appeared in places like the beaches and the Hamptons. A large fraction of people (5.5%) left the NYC area for other places across the US. For example, 0.37% of people left NYC for Florida, which is important to note because this kind of travel can bring the virus to new places.
- Normally, mobility and social contacts vary significantly by the demographic composition of a neighborhood. The social distancing policies have greatly reduced relative differences between different demographic groups as nearly everyone’s mobility and social contacts has been dramatically reduced.