COVID-19 vaccines are widely available in wealthy countries, yet many people remain unvaccinated. Understanding the effectiveness -- or lack thereof -- of popular vaccination campaign strategies is therefore critical. In this paper, we report results from two studies that tested strategies...

This paper is a practical guide (a toolkit) for researchers, students and practitioners wishing to introduce randomization as part of a research design in the field. It first covers the rationale for the use of randomization, as a solution to selection bias and a partial solution to publication...

During health crises, like COVID-19, individuals are inundated with messages promoting health-preserving behavior. Does additional light-touch messaging by a credible individual change behavior? Do the features of the message matter? To answer this, we conducted a large-scale messaging campaign...

During health crises, like COVID-19, individuals are inundated with messages promoting health-preserving behavior. Does additional light-touch messaging by a credible individual change behavior? Do the features of the message matter? To answer this, we conducted a large-scale messaging campaign...

COVID-19 vaccines are widely available in wealthy countries, yet many people remain unvaccinated. Understanding the effectiveness -- or lack thereof -- of popular vaccination campaign strategies is therefore critical. In this paper, we report results from two studies that tested strategies...