Data Donations for Digital Contact Tracing: Short- and Long-Term Effects of Monetary Incentives

Practice- and Policy-Oriented Abstract Data donations promise to unlock the social benefits of personal data. Recently, contact-tracing apps were developed to collect data from individuals to fight the COVID-19 pandemic. Because the success of these apps depends on widespread adoption and continuous data collection, we evaluate the effectiveness of monetary incentive mechanisms at promoting verified installations of the German Corona-Warn-App and short- and long-term data donations. We find monetary incentives are effective in the short term: They significantly increase app installations and short-term data donations, tripling the number of data donors after 14 days compared to no compensation. However, the positive stimulus of monetary incentives vanishes in the long term: After eight months, installers in treatments with monetary incentives are significantly more likely to have stopped donating data than intrinsically motivated installers who did not receive monetary incentives, as a consequence of experienced opportunity costs and a lack of perceived benefits. Consequently, long-term data donation rates are not significantly higher in treatments with monetary incentives. This suggests one-time payments are ineffective at promoting long-term data donations, as the short-term crowding-in of less intrinsically motivated installers is difficult to sustain when passive app usage limits opportunities for habit formation and convincing users of contact-tracing benefits.