Entry Deterrence and Free Riding in License Auctions: Incumbent Heterogeneity and Monotonicity

We examine free riding for entry deterrence in license auctions with heterogeneous incumbents. We establish the monotonicity of randomized preemptive bidding equilibria: an incumbent with a higher entry-loss rate has greater free-riding incentive, choosing a lower deterring probability. We then identify conditions for the existence of a series of fully or partially participating equilibria such that two or more incumbents with bounded heterogeneity in their entry-loss rates participate in randomized preemptive bidding. As an application, we examine a simple case of a bipartite group of participating incumbents consisting of one "leader"and many "followers". We show that the policy of limiting the leader's participation (set-asides for entrants, limiting participation of incumbents with excessive market shares, etc.) may or may not increase entry probability.