A medical treatment is said to have placebo effects if patients who are optimistic about the treatment respond better to the treatment. This paper proposes a simple test for placebo effects. Instead of comparing the treatment and control arms of a single trial, one should compare the treatment...

SARS struck Taiwan in 2003, causing a national crisis. Many people feared that SARS would spread through the health care system, and outpatient visits fell by more than 30% in the course of a few weeks. We examine how both public information and the behavior and opinions of peers contributed to...

The global spread of diseases such as swine flu and SARS highlights the difficult decision governments face when presented with evidence of a local outbreak. Reporting the outbreak may bring medical assistance but is also likely to trigger trade sanctions by countries hoping to contain the...

While conducting empirical work, researchers sometimes observe changes in outcomes before adoption of a new policy. The conventional diagnosis is that treatment is endogenous. This observation is also consistent, however, with anticipation effects that arise naturally out of many theoretical...