We present a general and tractable oligopoly model of multi-sided platforms with endogenous side and platform choices of heterogeneous end-users, considering any mix of single-homing and multi-homing platforms and in which participating on one side could preclude doing so on others. We show the...

Pharmaceutical firms spend increasing amounts in mergers and acquisitions (M&As), which raises the question of whether sufficient investment is left after mergers to further develop firms' internal drug development capability. We evaluate the effects of M&As on firms' post-merger R&D...