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Research draft

Nash equilibrium

vr.tr.nash-equilibrium · XCT.QLT

Let an agent explain Nash equilibrium, relay definitions, existence, refinements and applications from game theory and economics sources, describe the named concepts, and distinguish Nash equilibrium from Pareto optimality, dominant strategy equilibrium, minimax solutions and social optimum.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain Nash equilibrium, relay definitions, existence, refinements and applications from game theory and economics sources, describe the named concepts, and distinguish Nash equilibrium from Pareto optimality, dominant strategy equilibrium, minimax solutions and social optimum.

A solution concept in game theory, introduced by John Nash in 1950 and 1951, in which no player can improve their payoff by unilaterally changing strategy given the other players strategies, existing in mixed strategies for every finite game, with refinements and related concepts the registry aliases name such as pure strategy Nash equilibria, subgame perfect equilibrium introduced by Reinhard Selten, evolutionarily stable strategies from John Maynard Smith and George Price, and zero-sum and strictly determined games, where von Neumann s minimax theorem applies; Nash, Selten and Harsanyi shared the 1994 Nobel memorial prize in economics.

What it is for: Predicting stable outcomes in strategic interactions.

It can be explain the concept; relay existence and refinements; describe named concepts; distinguish related solution concepts.

Distinguishing features

No unilateral gain

Mixed strategy existence

May be inefficient

Many refinements

What it looks like

Not a visible object; shown as highlighted cells in payoff matrices.

Physical character

Nash s thesis: 1950 year

von Neumann minimax theorem: 1928 year

Nobel memorial prize: 1994 year - Nash, Harsanyi, Selten

How it is recognised

Strategy profile with no profitable unilateral deviation

Zero-sum game, finite two-player zero-sum game, strictly determined game, evolutionarily stable strategy, pure strategy Nash equilibrium, subgame perfect equilibrium

Pareto optimality maximises joint welfare; dominant strategies are best regardless; minimax applies to zero-sum; social optimum may differ

Related models

is a kind of - in registry terms

solution concept

was introduced by -

John Forbes Nash Jr.

includes - as a refinement

subgame perfect equilibrium

is contrasted with -

Pareto efficiency

In practice

Families and kinds

pure and mixed strategy equilibria

subgame perfect equilibria

Bayesian Nash equilibria

evolutionarily stable strategies

minimax solutions of zero-sum games

Standards and regulation

No regulation; used in competition and auction policy analysis

Failure modes and hazards

Assuming equilibria are socially optimal

Ignoring multiple equilibria

Overapplying rationality assumptions

Also called

zero-sum gamefinite two-player zero-sum gamestrictly determined gameevolutionarily stable strategypure strategy Nash equilibriumsubgame perfect equilibriumSequential equilibriumStrong Nash equilibriumMarkov perfect equilibrium

Where this came from

wikidata · CC0 1.0

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Understand What a Nash equilibrium is.

Science.

Definition

Definition.

Definition

Definition.

  1. What is a Nash equilibrium, and how does it differ from Pareto optimality, dominant strategies, minimax and social optimum? definition
  2. Is the question about maths, economics, biology or a specific game? boundary

Named

Named concepts.

Named

Named.

  1. What are zero-sum and strictly determined games, ESS, pure strategy and subgame perfect equilibria? definition
  2. Which entry fits the specific concept? action
Theory Theory.

Science.

Existence

Existence.

Existence

Existence.

  1. Why does every finite game have a mixed strategy equilibrium? provenance
  2. Which references are standard? provenance

Refinements

Refinements.

Refinements

Refinements.

  1. Why were refinements such as subgame perfection introduced? provenance
  2. Which sources are cited? provenance
Applications Applications.

Attribution.

Economics

Economics.

Economics

Economics.

  1. How is Nash equilibrium used in oligopoly, auctions and bargaining? provenance
  2. Which entry fits Cournot competition? action

Biology

Evolutionary game theory.

Biology

Biology.

  1. How do evolutionarily stable strategies apply to animal behaviour? provenance
  2. Which entry fits evolutionary game theory? action
Context Examples and critiques.

Context.

Dilemma

Prisoner s dilemma.

Dilemma

Dilemma.

  1. Why is mutual defection a Nash equilibrium in the prisoner s dilemma? provenance
  2. Which entry fits prisoner s dilemma? action

Behaviour

Behavioural critiques.

Behaviour

Behaviour.

  1. What do experiments show about when people play Nash equilibria, with findings attributed? provenance
  2. Which entry fits behavioral game theory? action

What the second pass must settle

  • Should the named refinements be separate entries?
  • How should game theory sources be linked?
  • How should behavioural critiques be presented?