Preventives are sold ex ante, before disease status is realized, while treatments are sold ex post. Even if the mean of the ex ante distribution of consumer values is the same as that ex post, the shape of the distributions may differ, generating a difference between the surplus each product can...

Kremer and Snyder (2015) show that demand curves for a preventive and treatment may have different shapes though they target the same disease, biasing the pharmaceutical manufacturer toward developing the lucrative rather than the socially desirable product. This paper tightens the theoretical...