Platform rules : multi-sided platforms as regulators

This paper provides a basic conceptual framework for interpreting non-price instruments used by multi-sided platforms (MSPs) by analogizing MSPs as "private regulators" who regulate access to and interactions around the platform. We present evidence on Facebook, TopCoder, Roppongi Hills and Harvard Business School to document the "regulatory" role played by MSPs. We find MSPs use nuanced combinations of legal, technological, informational and other instruments (including price-setting) to implement desired outcomes. Non-price instruments were very much at the core of MSP strategies.