9,348 research outputs found
Infinite sequential Nash equilibrium
In game theory, the concept of Nash equilibrium reflects the collective
stability of some individual strategies chosen by selfish agents. The concept
pertains to different classes of games, e.g. the sequential games, where the
agents play in turn. Two existing results are relevant here: first, all finite
such games have a Nash equilibrium (w.r.t. some given preferences) iff all the
given preferences are acyclic; second, all infinite such games have a Nash
equilibrium, if they involve two agents who compete for victory and if the
actual plays making a given agent win (and the opponent lose) form a
quasi-Borel set. This article generalises these two results via a single
result. More generally, under the axiomatic of Zermelo-Fraenkel plus the axiom
of dependent choice (ZF+DC), it proves a transfer theorem for infinite
sequential games: if all two-agent win-lose games that are built using a
well-behaved class of sets have a Nash equilibrium, then all multi-agent
multi-outcome games that are built using the same well-behaved class of sets
have a Nash equilibrium, provided that the inverse relations of the agents'
preferences are strictly well-founded.Comment: 14 pages, will be published in LMCS-2011-65
Sequential Games of Resource Extraction: Existence of Nash Equilibria
A general model for noncooperative extraction of common-property resource is considered. The main result is that this sequential game has a Nash equilibrium in stationary strategies. The proof is based on an infinite dimensional fixed-point theorem, and relies crucially on the topology of epi-convergence. A byproduct of the analysis is that Nash equilibrium strategies may be selected such that marginal propensities of consumption are bounded above by one.Sequential games, dynamic programming, fixed point theorem, Nash equilibrium, common property, natural resources, common property
Intelligent escalation and the principle of relativity
Escalation is the fact that in a game (for instance in an auction), the
agents play forever. The -game is an extremely simple infinite game with
intelligent agents in which escalation arises. It shows at the light of
research on cognitive psychology the difference between intelligence
(algorithmic mind) and rationality (algorithmic and reflective mind) in
decision processes. It also shows that depending on the point of view (inside
or outside) the rationality of the agent may change which is proposed to be
called the principle of relativity.Comment: arXiv admin note: substantial text overlap with arXiv:1306.228
On the Rationality of Escalation
Escalation is a typical feature of infinite games. Therefore tools conceived
for studying infinite mathematical structures, namely those deriving from
coinduction are essential. Here we use coinduction, or backward coinduction (to
show its connection with the same concept for finite games) to study carefully
and formally the infinite games especially those called dollar auctions, which
are considered as the paradigm of escalation. Unlike what is commonly admitted,
we show that, provided one assumes that the other agent will always stop,
bidding is rational, because it results in a subgame perfect equilibrium. We
show that this is not the only rational strategy profile (the only subgame
perfect equilibrium). Indeed if an agent stops and will stop at every step, we
claim that he is rational as well, if one admits that his opponent will never
stop, because this corresponds to a subgame perfect equilibrium. Amazingly, in
the infinite dollar auction game, the behavior in which both agents stop at
each step is not a Nash equilibrium, hence is not a subgame perfect
equilibrium, hence is not rational.Comment: 19 p. This paper is a duplicate of arXiv:1004.525
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