We examined this question under the scientific leadership of researchers from Hertie School, Humboldt-University of Berlin and University of Konstanz. Declarative data was fused with passive data from our behavioral panel. From 16 June (the launch of the app) until 21 September 2020 we analysed downloaded figures from the app from 1132 panelists and, in addition, asked them about their user behavior.

One group of participants were randomly selected, and were sent direct messages asking them to install the app. Subsequently, their app usage was compared to those who hadn’t received such messages on the basis of declarative and tracking data.

After high download figures in the first weeks following its launch in June 2020, their increase stagnated. The aim of the study was to track the numbers of downloads over 100 days and study the usage of the app in different sections of the population. The second stage of the study aimed to test strategies aimed at convincing more people to use the app.

The results of the study revealed that at the beginning of the study period a higher proportion of people from risk groups had been using the app, while people with many social contacts were rather more reluctant. At the same time, informative and motivating video messages did help to positively influence knowledge and attitudes towards the app, however, they didn’t have a positive effect on the download. Monetary incentives, on the contrary, led to a higher usage of the app, especially among younger respondents. Although the app usage in our panel was already relatively high, we achieved an increase of 17 percentage points on average, through financial incentives.

For this purpose, participants have been randomly allocated to one of two groups: one group was offered a monetary incentive to download the app (1, 2, or 5 euros), while the other group served as a control group.

The results of the study, on the one hand, indicate that the effectiveness of the app is limited because of a disadvantageous distribution of its usage among the population. At the same time, it offers solutions to considerably increase the number of users with comparably small monetary incentives.

The complete study can be found here.

*Germany’s contact-tracing-app designed to alert the user if they have had contact with a person infected with Covid.