Alphabet Inc.'s Google has published charts showing how the coronavirus has brought hard-hit Italy to a standstill, led to runs on grocery stores around the world and prompted a stark drop in going-out between Mardi Gras and St. Patrick’s Day.
The analysis of location data from billions of Google users’ phones is the largest public data set available to help health authorities assess if people are abiding with shelter-in-place and similar orders issued across the world to rein in the virus.
The company released reports for 131 countries with charts that compare traffic from Feb. 16 to March 29 to retail and recreational venues, train and bus stations, grocery stores and workplaces with a five-week period earlier this year.
Google said it published the reports to avoid any confusion about what it was providing to authorities, given the global debate that has emerged about balancing privacy-invasive location tracking with the need to prevent further outbreaks.
The data often correlated with the severity of outbreaks and the harshness and breadth of orders imposed by governments.
Italy and Spain, two of the hardest-hit countries, both saw visits to retail and recreation locations such as restaurants and movie theatres plunge 94 per cent. The United Kingdom, France and Philippines had declines of more than 80 per cent while India, which went into a sudden 21-day lockdown on March 25, was also notable at 77 per cent.
In the United States, where state responses have varied greatly, and in Australia, where good weather initially prompted many people to go the beach before social distancing measures were ratcheted up, the drops were less steep at under 50 per cent.
In contrast, in Japan and Sweden, where authorities have not imposed harsh restrictions, visits to retail and recreation sites fell by roughly only a quarter. While in South Korea, which has successfully contained a large outbreak through aggressive testing and contact tracing, the decline was just 19 per cent.
The data also underscore some challenges authorities have faced in keeping people apart. Grocery store visits surged in Singapore, the United Kingdom and elsewhere as travel restrictions were set to go into place. Visits to parks spiked in March in some San Francisco Bay Area counties under lockdown in California, forcing them to later put the sites off limits.
The data also underscores how the mood of people around the world has shifted. In New Orleans, during its annual Mardi Gras celebrations Feb. 16-25, which has with hindsight been criticized for helping spread the virus, there were off-the-chart increases in traffic to transit stations, parks and businesses.
But three weeks later in Dublin, heart of St. Patrick’s holiday celebrations, traffic was down at retail and recreational venues as the country ordered big events cancelled.
Within countries, there were wide gaps in behaviour by region. California, which was the first in the U.S. with a statewide lockdown, cut visits to retail and recreation locations by half. In New York State, the slide in such visits was gradual as officials waited to impose strict curbs but they eventually fell 62 per cent. By contrast, Arkansas, one of the few states without a sweeping lockdown, had the smallest decline at 29 per cent.
The coronavirus has infected more than 1 million people globally, and COVID-19, the respiratory illness it causes, has killed 52,000, according to a Reuters tally.
There were no reports for China and Iran, where Google services are blocked.
Data in Google’s reports come from users who enabled Google’s “Location History” feature on their devices. The company said it adopted technical measures to ensure that no individual could be identified through the new reports.
“These reports have been developed to be helpful while adhering to our stringent privacy protocols and policies,” Dr. Karen DeSalvo, chief health officer for Google Health and Jen Fitzpatrick, senior vice-president for Google Geo, wrote in a blog post.
China, Singapore, South Korea and other countries have asked residents to use apps and other technology to track their compliance with quarantines, but privacy activists argue such measures can compromise individual liberties.
Infectious disease specialists have said analyzing travel across groups by age, income and other demographics could help shape public service announcements.
Google, which infers demographics from users’ internet use as well as some data given when signing up to Google services, said it was not reporting demographic information. The company said, though, it was open to including additional information and countries in follow-up reports.
Google said consultations with officials in the U.S. and the World Health Organization helped inform the data shared.
The company declined to comment on whether it has received any legal requests to share more detailed data to help with efforts to tackle the pandemic.
Facebook Inc., which like Google has billions of users, has shared location data with non-governmental researchers that are producing similar reports for authorities in several countries. But the social media giant has not published any findings.
Sign up for the Coronavirus Update newsletter to read the day’s essential coronavirus news, features and explainers written by Globe reporters.