Thematic Clubs and the Supremacy of Network Externalities
We would like to thank the Editor Myrna Wooders for many helpful suggestions on an earlier draft, as well as Paul Belleflamme, António Brandão, Sofia Castro, Filomena Garcia, Didier Laussel, Yuri Nesterov, Frank Page, Joana Pinho, Nathalie Sonnac and Skerdilajda Zanaj for their comments and suggestions. Joana Resende acknowledges financial support from Cef.up and FCT through research grant PTDC/EGE‐ECO/115625/2009.
Abstract
We explore the issue of minorities' survival in the presence of positive network externalities. We rely on a simple example of thematic clubs to illustrate why and how such survival problems might appear, first considering the case of simple‐network effects (fully anonymous externalities) and then the case of cross‐network effects (type‐dependent externalities). In both cases, the analysis is framed as a simple noncooperative game with a continuum of players and binary action sets. There is a unique and interior Nash equilibrium under mild network effects and two corner equilibria under strong network effects, with one club driven out. A utilitarian planner would accentuate the clustering effects of network externalities, and call for the disappearance of the minority club more often than the noncooperative solution. A simple myopic learning algorithm capturing the progression of network lock‐in effects is studied.




