Do environmental conditions pose greater health risks to individuals living in urban or rural areas? The answer is theoretically ambiguous: while urban areas have traditionally been associated with heightened exposure to environmental pollutants, the economies of scale and density inherent to...

Local opinion leaders may play a key role in easing information frictions associated with technology adoption. This paper analyzes the influence of physician investigators who lead pivotal clinical trials for new cancer drugs. By comparing diffusion patterns across many drugs, we separate...