During the COVID-19 epidemic, many health professionals started using mass communication on social media to relay critical information and persuade individuals to adopt preventative health behaviors. Our group of clinicians and nurses developed and recorded short video messages to encourage...

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...

Collects papers from Hugo Sonnenschein's students with the aim of demonstrating his impact as an advisor. Each paper in this work is accompanied with a preface by the student that provides background on the paper and indicates Hugo's influence on its genesis. All papers herin, lie in...

We examine how peers influence the allegiances of West Point cadets in the American Civil War. Specifically, we analyze how quasi-random variations in the proportion of cadets from northern (low-slave) states influenced the decisions of cadets in choosing which army to join. A higher proportion...

We examine friendships and study partnerships among university students over several years. At the aggregate level, connections increase over time, but homophily on gender and ethnicity is relatively constant across time, university residences, and different network layers. At the individual...