WORKING PAPER | ISSUE 01/2021 | UPDATED VERSION 15 JUNE 2021PLATFORM MERGERS AND ANTITRUSTGEOFFREY PARKER, GEORGIOS PETROPOULOS AND MARSHALL VAN ALSTYNEPlatform ecosystems rely on economies of scale, data-driven economies of scope, high quality algorithmic systems, and strong network effects that frequently promote winner-takes-most markets. Some platform firms have grown rapidly and their merger and acquisition strategies have been very important factors