"The quality of medical care received by patients varies for two reasons: differences in doctors' competence or differences in doctors' incentives. Using medical vignettes, the authors evaluated competence for a sample of doctors in Delhi. One month later, they observed the same doctors in their...

If infectious people can infect other people, who in turn can infect others, and so on--the pure infection externality--government subsidies to affect private behavior should equally favor preventive and curative activities, if people recover to become susceptible again. Otherwise, other subsidy...