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...

Pre-Analysis Plans (PAPs) for randomized evaluations are becoming increasingly common in Economics, but their definition remains unclear and their practical applications therefore vary widely. Based on our collective experiences as researchers and editors, we articulate a set of principles for...

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...

Formal financial institutions can have far-reaching and long-lasting impacts on informal lending and information networks. We first study 75 villages in Karnataka, 43 of which were exposed to microfinance after we first collected detailed network data. Networks shrink more in exposed villages....

Can microcredit help unlock a poverty trap for some people by putting their businesses on a different trajectory? Could the small microcredit treatment effects often found for the average household mask important heterogeneity? In Hyderabad, India, we find that "gung ho entrepreneurs" (GEs),...

Should police activity be narrowly focused and high force, or widely-dispersed but of moderate intensity? Critics of intense "hot spot" policing argue it primarily displaces, not reduces, crime. But if learning about enforcement takes time, the police may take advantage of this period to...