Covid-19 Infections and Unknown Numbers: Are We Comparing Apples and Oranges?

In fall 2020, the number of new coronavirus infections recorded is increasing throughout Europe. While many politicians are warning of growing dangers, critics accuse them of panic-mongering and claim that the rising infection figures are simply the result of increased testing, not an increased spread of the virus. Our analysis shows that it is indeed misleading to directly compare the figures for new infections recorded in Germany in spring with the current numbers of new infections. However, it does not follow from this that the increasing numbers are caused by more tests alone. We use a simple simulation calculation to show that the current figures do indeed indicate an increased incidence of infection. At the same time, it is exaggerated to equate the situation at the beginning of October in Germany with the situation in the first half of April. If the same number of tests had been carried out in spring, similar numbers of new infections would not have been measured until early May 2020. A balanced and realistic interpretation of the infection situation is important to enable appropriate reactions from both political and economic decision-makers.