This paper analyzes the optimal contract for a consumer to procure a credence good from an expert when (i) the expert might misrepresent his private information about the consumer's need, (ii) the expert might not choose the requested service since his choice of treatment is non-observable, and (iii) limited liability of the expert precludes imposing penalty payments on him. We characterize payments under the optimal contract and show that, compared with the first-best, these induce inefficient undertreatment. We further show that separating diagnosis and treatment increases consumer surplus. Whether it decreases or increases the likelihood of undertreatment, however, depends on the accuracy of the expert's information.
credence goods non-observable treatments hidden information moral hazard limited liability