Efficient Liability in Expert Markets

When providing professional services, an expert may misbehave by either prescribing “wrong” treatment for consumer's problem or failing to exert proper effort to diagnose it. We show that under a range of liabilities the expert will recommend the appropriate treatment based on his private information if markups for alternative treatments are close enough; however, a well‐designed liability rule is essential for also motivating efficient diagnosis effort. We further demonstrate that unfettered price competition between experts may undermine the efficient role of liability, whereas either a minimum‐price constraint or an obligation‐to‐serve requirement can restore it.