Paul Heidhues is a professor of behavioral and competition economics at Heinrich Heine University Düsseldorf. He worked on numerous topics in Industrial Organization and Competition Policy such as input-market bargaining power, merger control, and collusion. More recently, much of his work focuses on the functioning of markets when consumers are partly driven by psychological factors – such as social preferences, loss aversion, time-inconsistency, or naivete – that the classic consumer model abstracts from. Among other things, he has written on how firms optimally price products and design credit contracts in response to consumers' psychological tendencies, and he has investigated the implications of various consumer mistakes for the functioning of markets and for consumer-protection regulation.