Information Greenhouse: Optimal Persuasion for Medical Test-Avoiders

Abstract

Patients often avoid medical tests because the information they provide, although medically useful, is psychologically painful. This paper studies optimal communication between a doctor and an information-avoidant patient who can refuse testing and treatment. I characterize when optimal communication creates an information greenhouse, a commitment to reward participation with comforting information about the untreated prognosis. When testing is voluntary and the patient is unwilling to be tested under extreme pessimism, an information greenhouse is optimal and takes the form of committed comfort, which provides reassuring information after the test. When the patient can reject the consultation at the outset and the patient's prior belief about the untreated prognosis is intermediate, an information greenhouse is optimal and takes the form of precautionary comfort, which provides reassuring information before the test. In all other cases in which the patient can be persuaded, warning-based policies that trigger pessimism prevail.