Study Shows the Effectiveness of Social Distancing

Within three weeks, early measures to restrict personal contact and close schools prevented over 80% of COVID infections and over 60% of deaths in Germany.

Professor Ulrich Glogowsky
Professor Ulrich Glogowsky

In the following three weeks after reducing the populations’ mobility and implementing measures adopted in mid-March 2020 to contain the COVID-19 pandemic, these measures effectively limited the spread of COVID-19. A recent study conducted by an international team of economists led by Professor Ulrich Glogowsky (JKU) and Junior Professor Dr. Emanuel Hansen (Faculty of Economics and Social Sciences at the University of Cologne) showed just how important early political measures were in containing the spread of the coronavirus in Germany. The study was published in the interdisciplinary open-access journal PLoS ONE.

The COVID-19 pandemic spread rapidly across Europe during the spring of 2020. In mid-March, after initial hesitation, the German government and the Conference of Prime Ministers quickly decided on a series of policies to restrict social contact, including closing schools, kindergartens, and retail. People were told not to hold gatherings with people from different households in their private homes. In this regard, German policy-makers quickly implemented far-reaching restrictions in terms of contact to others. During the initial stages in the first wave, wearing a face mask was not yet mandatory and rapid testing and the vaccination was not yet available. Within a few weeks, COVID-19 infections in Germany declined sharply up until contact restrictions were gradually loosened beginning April 20, 2020.

Despite the rapid decline in Germany’s infection rate, both the public and experts repeatedly expressed their doubt in regard to just how effective restricting contact to others was. There were arguments that the spread would have slowed even without measures and mandates and just by citizens changing their behavior.

In an effort to address this controversial question, the team of authors implemented a quasi-experimental analysis procedure to estimate the causal effect of policy measures in over 400 German counties using detailed information provided by the Robert Koch Institute as well as anonymized movement information provided by private mobile phone providers.

In doing so, the authors came to interesting conclusions: First, they studied mobile phone data and determined that the policies reduced people's physical movements by an average of 30%, as desired. Second, they found evidence of effective containment during the pandemic as within the first three weeks, contact restrictions in Germany prevented over 80% of COVID infections and over 60% of the resulting deaths that would have occurred had the measures not been implemented. In other words, according to the researchers' assessments, without the measures in place, there would have been approximately 500,000 additional infections and approximately 5,400 additional deaths in Germany by early April alone.