How to better communicate exponential growth of infectious diseases

Exponential growth bias is the phenomenon that humans underestimate exponential growth. In the context of infectious diseases, this bias may lead to failure to understand the effectiveness of non-pharmaceutical interventions (NPIs). Communicating the same scenario in different ways (framing) has been found to have a large impact on people’s evaluations and behavior in the contexts of social behavior, risk taking and health care. We find that framing matters for people’s assessment of the benefits of NPIs. In two commonly used frames, most subjects in our experiment drastically underestimate the number of cases NPIs avoid. Framing growth in terms of doubling times, rather than growth rates, reduces bias. When the scenario is framed in terms of time gained, rather than cases avoided, the median subject assesses the benefit of NPIs correctly. These findings suggest changes that public health authorities can adopt to better communicate the exponential spread of infectious diseases.