This online appendix to "Insulated Platform Competition" includes proofs and details of our applications.The paper to which these Appendices apply is available at the following URL: "http://ssrn.com/abstract=1694317" http://ssrn.com/abstract=1694317

Does competition promote efficient platform pricing and market structures? We model imperfect platform competition using a new approach, Insulated Equilibrium (IE). Building on the observation that platforms often charge low prices to build a "critical mass", IE assumes platforms use...

Should banks (through Visa) be allowed to own debit clearing networks? This problem combines the classic Cournot (1838)-Spengler (1950) double marginalization problem with the more recent literature on two-sided markets (Rochet and Tirole, 2003). Because both the double marginalization (Weyl,...

I develop a general theory of monopoly pricing of networks. Platforms use insulating tariffs to avoid coordination failure, implementing any desired allocation. Profit-maximization distorts in the spirit of Spence (1975) by internalizing only network externalities to marginal users. Thus the...

Successful platforms attract not just many users, but also those of the right kind. "The right kind of user" is one who can either be directly monetized or who differentially attracts other valuable users. Bonacich centrality on the network of user sorting with direct value of monetization...