Quantal Response Equilibrium

Quantal response equilibrium (QRE) is a solution concept in game theory. First introduced by Richard McKelvey and Thomas Palfrey, it provides an equilibrium notion with bounded rationality. QRE is not an equilibrium refinement, and it can give significantly different results from Nash equilibrium. QRE is only defined for games with discrete strategies, although there are continuous-strategy analogues.

In a quantal response equilibrium, players are assumed to make errors in choosing which pure strategy to play. The probability of any particular strategy being chosen is positively related to the payoff from that strategy. In other words, very costly errors are unlikely.

The equilibrium arises from the realization of beliefs. A player's payoffs are computed based on beliefs about other players' probability distribution over strategies. In equilibrium, a player's beliefs are correct.

Read more about Quantal Response Equilibrium:  Application To Data, Logit Equilibrium, For Dynamic Games

Famous quotes containing the words response and/or equilibrium:

    It does me good to write a letter which is not a response to a demand, a gratuitous letter, so to speak, which has accumulated in me like the waters of a reservoir.
    Henry Miller (1891–1980)

    They who feel cannot keep their minds in the equilibrium of a pair of scales: fear and hope have no equiponderant weights.
    Horace Walpole (1717–1797)