PRODUCT HOPPING AND INNOVATION INCENTIVES

We study innovation incentives under “product hopping,” whereby an incumbent patents a minor modification of a pioneer drug (for example, a new delivery method) and promotes the modified version to shift demand from the original drug. We develop a model in which an incumbent races against an entrant to discover a drastic innovation. We show that product hopping can decrease the total research and development (R&D) investment for drastic innovation. Moreover, an incumbent only chooses to engage in product hopping when drastic innovation is sufficiently difficult. Although product hopping may boost ex-ante R&D for pioneer drugs, it comes at the expense of decreasing R&D for subsequent drastic innovations and consumer surplus through socially wasteful marketing expenses. Our results contribute to the policy debate on product hopping, welfare, and antitrust.