https://www.sciencedaily.com/releases/2020/08/200803120134.htm

The current COVID-19 pandemic has prompted countries around the world to institute travel bans restricting the influx of visitors from especially countries where the spread of the virus is still rampant. Such restrictions, as well as other measures put in place by governments to curb the spread of COVID-19, have been heavily criticized in both political and public debate, prompting many to wonder how effective current measures aimed at reducing the spread of the pandemic really are. To address this uncertainty, IIASA researchers examined how the virus is spread regionally as well as between countries, and how this develops over time. The study's surprising results have been published in Letters in Spatial and Resource Sciences.

According to the authors, the majority of studies about transmission of COVID-19 tend to focus on specific countries. This study however, explored a much wider cross-section of countries and used approaches more commonly applied to estimate regional transmission of economic quantities (such as GDP or trade). The main questions that the researchers wanted to address were, on the one hand, whether governmental measures have actively been reducing the cross-border transmission of COVID-19 cases and, on the other hand, which channels were the main sources of transmission across national borders.