Antitrust, Regulation, and User Union in the Era of Digital Platforms and Big Data

We model platform competition with network effects, infrastructure investment, and data collection and sharing, thereby providing a unifying framework to evaluate data-related regulation and antitrust policies. Data feedback improves service quality but may concentrate market power. Dispersed users do not internalize the impact of their data contribution on (i) other users, (ii) market concentration, and (iii) platforms’ incentives to invest in data infrastructure, causing inefficient over- or under-collection of data. Data sharing proposals, user privacy protections, platform commitments and markets for data cannot fully address these inefficiencies. We propose and model user union, which represents and coordinates users, as an effective solution for consumer protection