South Korea is a standout in the current battle against COVID-19, largely due to its widespread testing and contact tracing; however, key to its innovation is publicly disclosing detailed information on the individuals who test positive for COVID-19. These measures prove more effective at reducing deaths among than comprehensive stay-home orders, according to new research from University of California San Diego, Pennsylvania State University and the University of Chicago.
The COVID-19 outbreak was identified in both South Korea and in the United States on Jan. 13. As of May 22, South Korea had 11,142 cases and the United States had 1,571,617. From day one of the spread of the virus, South Koreans received text messages whenever new cases were discovered in their neighborhood, as well as information and timelines of infected persons’ travel.
In a new National Bureau of Economic Research (NBER) working paper, researchers combined detailed foot-traffic data in Seoul from South Korea’s largest mobile phone company with publicly disclosed information on the location of individuals who had tested positive. The results reveal that public disclosure can help people target their social distancing and this proves especially helpful for vulnerable populations who can more easily avoid areas with a higher rate of infection.
“Our data shows that South Korea’s public disclosure information was effective in changing citizens’ behavior to drive down the rate of infection, without government-imposed lockdowns,” said co-author Munseob Lee, an assistant professor of economics at UC San Diego’s School of Global Policy and Strategy. “This pattern is particularly pronounced during the weekends and among those over the age of 60.”
Seoul, with almost 10 million inhabitants, is one of the most densely populated cities in the world. Yet, as of May 22 the city had only 758 confirmed cases and three deaths.
“These numbers are remarkably low in comparison to cities of similar size,” the authors of the NBER paper write.
The city did not implement wide-spread social isolation restrictions; however, like other local governments in the country, the capitol provided inhabitants information in real time via text messages on individuals that had tested positive. In addition, the Seoul Metropolitan Government developed a dedicated website and a mobile app to enable residents to access real-time information.
Loss of privacy and benefits of public disclosure
A typical alert can contain the infected persons’ age and gender, and a detailed log of their movements, which is based on contact tracing combined with data from cell phone and credit card records.
This strategy was made possible because South Korean laws on managing and publicly sharing information on patients of infectious diseases changed significantly after the MERS outbreak in 2015. In the event of a national health emergency, the country’s laws empower the Korea Centers for Disease Control Prevention to use GPS data, surveillance camera footage and credit card transactions to recreate infected persons’ route a day before their symptoms showed.
According to the authors, this publicly available data spurred significant changes in the commuting patterns of people: individuals were more likely to commute to the districts with less confirmed cases, and less likely to commute to the districts with more cases.
“To be clear, disclosure of public information infringes upon the privacy of the affected individuals,” said Chang-Tai Hsieh of the University of Chicago. “We do not attempt to measure the cost of the loss of privacy, but whenever such measures are available, they can be compared against the benefits of public disclosure we provide here.”