Fabrizio Germano

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We construct an uncoupled randomized strategy of repeated play such that, if every player plays according to it, mixed action profiles converge almost surely to a Nash equilibrium of the stage game. The strategy requires very little in terms of information about the game, as players' actions are based only on their own past payoffs. Moreover, in a variant(More)
We show that every N-player K 1 × · · · × K N game possesses a correlated equilibrium with at least N i=1 K i − 1 − N i=1 K i (K i − 1) zero entries. In particular, the largest N-player K ×· · ·×K games with unique fully supported correlated equilibrium are two-player games. 1 The result Consider an N-player K 1 × · · · × K N normal form game γ = (N, S, {γ(More)
This paper studies the evolution of boundedly rational rules for playing normal form games within environments of stochastically varying games. Essentially, i t i s s h o wn that many of the \folk results" of evolutionary game theory, t ypically obtained with a xed game, carry over to corresponding stochastic dynamics over rules for playing stochastically(More)
Standard media economics models imply that increased platform competition decreases ad levels and that mergers reduce per-viewer ad prices. The empirical evidence, however, is mixed. We attribute the theoretical predictions to the combined assumptions that there is no advertising congestion and that viewers single-home. Allowing for crowding in viewer(More)
We extend Kohlberg and Mertens' (1986) structure theorem concerning the Nash equilibrium correspondence to show that its graph is not only homeomorphic to the underlying space of games but that it is also unknotted. This is then shown to have some basic consequences for dynamics whose rest points are Nash equilibria. * We would like to thank Eddie Dekel and(More)
Within a simple model of non-localized, Hotelling-type competition among arbitrary numbers of media outlets we characterize quality and content of media under different ownership structures. Assuming advertising-sponsored, profit-maximizing outlets, we show that (i) topics sensitive to advertisers can be underreported (self-censored) by all outlets in the(More)
Two basic properties concerning the dynamic behavior of competitive equilibria of exchange economies with complete markets are derived essentially from the fact that the Walras correspondence has no knots. I. One can view the work of Debreu, E. and H. Dierker, Balasko and others that introduced the notions of regular economy and regular equilibrium , and(More)
Equivalence classes of normal form games are deened using the discontinuities of correspondences of standard equilibrium concepts like correlated, Nash, and robust equilibrium, or risk dominance and rationalizability. Resulting equivalence classes are fully characterized and compared across diierent equilibrium concepts for 2 2 gamess larger games are also(More)