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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    A Short Introduction to Game Theory

    Heiko Hotz

    July 13, 2006

    Heiko Hotz A Short Introduction to Game Theory

    http://goforward/http://find/http://goback/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    http://find/http://goback/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    http://find/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    I d i

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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    I t d ti

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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    Introd ction

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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Table of Contents

    1 Introduction

    2

    Definitions3 Games

    4

    Evolutionary Game Theory5 Applications

    6 Outlook

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    http://find/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Introduction

    Game Theory - What is it?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    http://find/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Generally, game theory investigates conflict situations, theinteraction between the agents and their decisions.

    A game in the sense of game theory is given by a (mostlyfinite) number of players, who interact according to givenrules.

    The subject of game theory are situations, where the result for

    a player does not only depend on his own decisions, but also

    on the behaviour of the other players.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Generally, game theory investigates conflict situations, theinteraction between the agents and their decisions.

    A game in the sense of game theory is given by a (mostlyfinite) number of players, who interact according to givenrules.

    The subject of game theory are situations, where the result for

    a player does not only depend on his own decisions, but alsoon the behaviour of the other players.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    http://find/
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    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Generally, game theory investigates conflict situations, theinteraction between the agents and their decisions.

    A game in the sense of game theory is given by a (mostlyfinite) number of players, who interact according to givenrules.

    The subject of game theory are situations, where the result for

    a player does not only depend on his own decisions, but alsoon the behaviour of the other players.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Figure: Johnvon Neumann

    Game theory has its historical origin in 1928.By analysing parlour games, John vonNeumann realised very quickly thepracticability of his approaches forthe analysis of economic problems.

    In his book Theory of Games andEconomic Behavior, which he wrote together

    with Oskar Morgenstern in 1944, he already applied hismathematical theory to economic applications.

    The publication of this book is generally seen as the initialpoint of modern game theory.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Figure: Johnvon Neumann

    Game theory has its historical origin in 1928.By analysing parlour games, John vonNeumann realised very quickly thepracticability of his approaches forthe analysis of economic problems.

    In his book Theory of Games andEconomic Behavior, which he wrote together

    with Oskar Morgenstern in 1944, he already applied hismathematical theory to economic applications.

    The publication of this book is generally seen as the initialpoint of modern game theory.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - What is it?

    Figure: Johnvon Neumann

    Game theory has its historical origin in 1928.By analysing parlour games, John vonNeumann realised very quickly thepracticability of his approaches forthe analysis of economic problems.

    In his book Theory of Games andEconomic Behavior, which he wrote together

    with Oskar Morgenstern in 1944, he already applied hismathematical theory to economic applications.

    The publication of this book is generally seen as the initialpoint of modern game theory.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionD fi i i

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Introduction

    Game Theory - where is it applied?

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionD fi iti

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - Where is it applied?

    When there is competition for a resource to be analysed,game theory can be used either to explain existing behaviouror to improve strategies.

    The first is especially applied by sciences which analyselong-term situations, like biology or sociology.

    In animality, for example, one can find situations, wherecooperation has developed for the sake of mutual benefits.

    The latter is a crucial tool in sciences like economics.Companies use game theory to improve their strategicalsituation in the market.

    Many more sciences like sociology, philosophy, psychology andcultural anthropology use game theory as an appropriate tool.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - Where is it applied?

    When there is competition for a resource to be analysed,game theory can be used either to explain existing behaviouror to improve strategies.

    The first is especially applied by sciences which analyselong-term situations, like biology or sociology.

    In animality, for example, one can find situations, wherecooperation has developed for the sake of mutual benefits.

    The latter is a crucial tool in sciences like economics.Companies use game theory to improve their strategicalsituation in the market.

    Many more sciences like sociology, philosophy, psychology andcultural anthropology use game theory as an appropriate tool.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - Where is it applied?

    When there is competition for a resource to be analysed,game theory can be used either to explain existing behaviouror to improve strategies.

    The first is especially applied by sciences which analyselong-term situations, like biology or sociology.

    In animality, for example, one can find situations, wherecooperation has developed for the sake of mutual benefits.

    The latter is a crucial tool in sciences like economics.Companies use game theory to improve their strategicalsituation in the market.

    Many more sciences like sociology, philosophy, psychology andcultural anthropology use game theory as an appropriate tool.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - Where is it applied?

    When there is competition for a resource to be analysed,game theory can be used either to explain existing behaviouror to improve strategies.

    The first is especially applied by sciences which analyselong-term situations, like biology or sociology.

    In animality, for example, one can find situations, wherecooperation has developed for the sake of mutual benefits.

    The latter is a crucial tool in sciences like economics.Companies use game theory to improve their strategicalsituation in the market.

    Many more sciences like sociology, philosophy, psychology andcultural anthropology use game theory as an appropriate tool.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    http://find/
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    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Game Theory - What is it?Game Theory - Where is it applied?

    Game Theory - Where is it applied?

    When there is competition for a resource to be analysed,game theory can be used either to explain existing behaviouror to improve strategies.

    The first is especially applied by sciences which analyselong-term situations, like biology or sociology.

    In animality, for example, one can find situations, wherecooperation has developed for the sake of mutual benefits.

    The latter is a crucial tool in sciences like economics.Companies use game theory to improve their strategicalsituation in the market.

    Many more sciences like sociology, philosophy, psychology andcultural anthropology use game theory as an appropriate tool.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    N l F G

    http://find/
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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Normal Form GamesExtensive Form GamesNash Equilibrium

    Definitions

    Normal Form Games

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    Normal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Normal Form GamesExtensive Form GamesNash Equilibrium

    Normal Form Games

    A game in normal form consists of:

    1

    A finite number of players.2 A strategy set assigned to each player.

    3 A payoff function, which assigns a certain payoff to eachplayer depending on his strategy and the strategy of the otherplayers.

    Both players choose their strategy simultaneously

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    Normal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Normal Form GamesExtensive Form GamesNash Equilibrium

    Normal Form Games

    A game in normal form consists of:

    1

    A finite number of players.2 A strategy set assigned to each player.

    3 A payoff function, which assigns a certain payoff to eachplayer depending on his strategy and the strategy of the otherplayers.

    Both players choose their strategy simultaneously

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    Normal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Normal Form GamesExtensive Form GamesNash Equilibrium

    Normal Form Games

    A game in normal form consists of:

    1

    A finite number of players.2 A strategy set assigned to each player.

    3 A payoff function, which assigns a certain payoff to eachplayer depending on his strategy and the strategy of the otherplayers.

    Both players choose their strategy simultaneously

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GNormal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Normal Form GamesExtensive Form GamesNash Equilibrium

    Normal Form Games

    A game in normal form consists of:

    1

    A finite number of players.2 A strategy set assigned to each player.

    3 A payoff function, which assigns a certain payoff to eachplayer depending on his strategy and the strategy of the otherplayers.

    Both players choose their strategy simultaneously

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GNormal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Extensive Form GamesNash Equilibrium

    Payoff Matrix

    If the number of players is limited to two and if their sets ofstrategies consist of only a few elements, the outcome of thepayoff function can be represented in a matrix, the so-calledpayoff matrix, which shows the two players, their strategiesand their payoffs:

    Player1\Player2 L R

    U 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Extensive Form GamesNash Equilibrium

    Payoff Matrix

    If the number of players is limited to two and if their sets ofstrategies consist of only a few elements, the outcome of thepayoff function can be represented in a matrix, the so-calledpayoff matrix, which shows the two players, their strategiesand their payoffs:

    Player1\Player2 L R

    U 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form Games

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Extensive Form GamesNash Equilibrium

    Definitions

    Extensive Form Games

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form Games

    G

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Extensive Form GamesNash Equilibrium

    Extensive Form Games

    Contrary to the normal form game, the rules of an extensive formgame are described such that the agents of the game execute theirmoves consecutively.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form GamesE i F G

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    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Extensive Form GamesNash Equilibrium

    Definitions

    Nash Equilibrium

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form GamesE t i F G

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Extensive Form GamesNash Equilibrium

    Nash Equilibrium

    If each player has chosen a strategy and no player can benefit bychanging his strategy while the other players keep theirs

    unchanged, then the current set of strategy choices and thecorresponding payoffs constitute a Nash equilibrium.

    Figure:John Nash

    John Nash showed in 1950, that every game with a

    finite number of players and finite numberof strategies has at least one mixed strategyNash equilibrium.

    Heiko Hotz A Short Introduction to Game Theory

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    GamesNormal Form GamesExtensive Form Games

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Extensive Form GamesNash Equilibrium

    Nash Equilibrium

    If each player has chosen a strategy and no player can benefit bychanging his strategy while the other players keep theirs

    unchanged, then the current set of strategy choices and thecorresponding payoffs constitute a Nash equilibrium.

    Figure:John Nash

    John Nash showed in 1950, that every game with a

    finite number of players and finite numberof strategies has at least one mixed strategyNash equilibrium.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesNormal Form GamesExtensive Form Games

    http://find/http://goback/
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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Extensive Form GamesNash Equilibrium

    Nash Equilibrium

    In a pure strategies, one strategy is played with probability 1.

    A mixed strategy is a linear combination of at least two purestrategies.

    The coefficients denote the probabilities of the pure strategiesto be played.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesG ( G )

    Normal Form GamesExtensive Form Games

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Extensive Form GamesNash Equilibrium

    Nash Equilibrium

    In a pure strategies, one strategy is played with probability 1.

    A mixed strategy is a linear combination of at least two purestrategies.

    The coefficients denote the probabilities of the pure strategiesto be played.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    E l ti G Th (EGT)

    Normal Form GamesExtensive Form Games

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Extensive Form GamesNash Equilibrium

    Nash Equilibrium

    In a pure strategies, one strategy is played with probability 1.

    A mixed strategy is a linear combination of at least two purestrategies.

    The coefficients denote the probabilities of the pure strategiesto be played.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    E ol tionar Game Theor (EGT)

    Normal Form GamesExtensive Form Games

    http://find/http://goback/
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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Nash Equilibrium

    Best Response

    The best response is the strategy (or strategies)

    which produces the most favorable immediate

    outcome for the current player, taking other players

    strategies as given.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form Games

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form Games

    http://find/http://goback/
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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form GamesN h E ilib i

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form GamesN h E ilib i

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    Evolutionary Game Theory (EGT)Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    y y ( )Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    ( )Applications

    Outlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5

    D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    ApplicationsOutlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)A li i

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    ApplicationsOutlook

    Nash Equilibrium

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)A li ti

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    ApplicationsOutlook

    s q

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Normal Form GamesExtensive Form GamesNash Equilibrium

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    ApplicationsOutlook

    q

    Localizing a Nash Equilibrium in a Payoff Matrix

    Player1\Player2 L RU 3 , 3 0 , 5D 5 , 0 1 , 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

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    ApplicationsOutlook

    Games

    Prisoners Dilemma

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/http://goback/
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    ApplicationsOutlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/http://goback/
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    ApplicationsOutlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://goforward/http://find/http://goback/
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    ppOutlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    ppOutlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/http://goback/
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    Outlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    Applications

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Outlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsO l k

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    54/145

    Outlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsO tl k

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    55/145

    Outlook

    Prisoners Dilemma

    Two suspects arrested

    Police has insufficient evidence for a conviction

    If both testify:Both receive 2-year sentence

    If both stay silent:

    Only a six-month-sentence for a minor charge

    If one testifies and the other remains silent:Betrayer goes free, accomplice receives 10-year sentence

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Outlook

    Payoff Matrix of the Prisoners Dilemma

    Abbreviations: To testify means to betray the other suspectand thus to defect (D), to remain silent means to cooperate(C) with the other suspect.

    We will use positive numbers in the payoff matrix.

    Player1\Player2 C D

    C 3, 3 0, 5D 5, 0 1, 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Outlook

    Payoff Matrix of the Prisoners Dilemma

    Abbreviations: To testify means to betray the other suspectand thus to defect (D), to remain silent means to cooperate(C) with the other suspect.

    We will use positive numbers in the payoff matrix.

    Player1\Player2 C D

    C 3, 3 0, 5D 5, 0 1, 1

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Outlook

    Games

    Public Good Game

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Outlook

    Public Good Game

    A group of 4 people are given $ 200 each.

    They can invest an amount of money in a project.

    Every $1 invested will yield $ 2, which would be distributed toall group members.

    If everyone invested, each would get $ 400.

    However, if only one person invested, that sucker wouldtake home a mere $ 100.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Public Good Game

    A group of 4 people are given $ 200 each.

    They can invest an amount of money in a project.

    Every $1 invested will yield $ 2, which would be distributed toall group members.

    If everyone invested, each would get $ 400.

    However, if only one person invested, that sucker wouldtake home a mere $ 100.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Public Good Game

    A group of 4 people are given $ 200 each.

    They can invest an amount of money in a project.

    Every $1 invested will yield $ 2, which would be distributed toall group members.

    If everyone invested, each would get $ 400.

    However, if only one person invested, that sucker wouldtake home a mere $ 100.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://goforward/http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Public Good Game

    A group of 4 people are given $ 200 each.

    They can invest an amount of money in a project.

    Every $1 invested will yield $ 2, which would be distributed toall group members.

    If everyone invested, each would get $ 400.

    However, if only one person invested, that sucker wouldtake home a mere $ 100.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Public Good Game

    A group of 4 people are given $ 200 each.

    They can invest an amount of money in a project.

    Every $1 invested will yield $ 2, which would be distributed toall group members.

    If everyone invested, each would get $ 400.

    However, if only one person invested, that sucker wouldtake home a mere $ 100.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Payoff Function of the Public Good Game

    This is a game in normal form and therefore has a payoff functionfor each player. The payoff function for, lets say, player 1 is givenby

    P1 = 2 (s1 + s2 + s3 + s4)4

    s1

    =2 (s2 + s3 + s4)

    4 0, 5 s1

    Every investment s1 of player 1 will diminish his payoff.

    Therefore, a rational player will choose the strategy sn = 0,i.e. he will invest no money at all.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Payoff Function of the Public Good Game

    This is a game in normal form and therefore has a payoff functionfor each player. The payoff function for, lets say, player 1 is givenby

    P1 = 2 (s1 + s2 + s3 + s4)4

    s1

    =2 (s2 + s3 + s4)

    4 0, 5 s1

    Every investment s1 of player 1 will diminish his payoff.

    Therefore, a rational player will choose the strategy sn = 0,i.e. he will invest no money at all.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Payoff Function of the Public Good Game

    This is a game in normal form and therefore has a payoff functionfor each player. The payoff function for, lets say, player 1 is givenby

    P1 = 2 (s1 + s2 + s3 + s4)4

    s1

    =2 (s2 + s3 + s4)

    4 0, 5 s1

    Every investment s1 of player 1 will diminish his payoff.

    Therefore, a rational player will choose the strategy sn = 0,i.e. he will invest no money at all.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Payoff Function of the Public Good Game

    This is a game in normal form and therefore has a payoff functionfor each player. The payoff function for, lets say, player 1 is givenby

    P1 = 2 (s1 + s2 + s3 + s4)4

    s1

    =2 (s2 + s3 + s4)

    4 0, 5 s1

    Every investment s1 of player 1 will diminish his payoff.Therefore, a rational player will choose the strategy sn = 0,i.e. he will invest no money at all.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Payoff Function of the Public Good Game

    This is a game in normal form and therefore has a payoff functionfor each player. The payoff function for, lets say, player 1 is givenby

    P1 = 2 (s1 + s2 + s3 + s4)4

    s1

    =2 (s2 + s3 + s4)

    4 0, 5 s1

    Every investment s1 of player 1 will diminish his payoff.Therefore, a rational player will choose the strategy sn = 0,i.e. he will invest no money at all.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Games

    Rock, Paper, Scissors

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Rock, Paper, Scissors

    Two players form a symbol (rock, paper or scissors) with theirhands

    Rock crushes ScissorsScissors cut Paper

    Paper covers Rock

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    http://find/
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    Rock, Paper, Scissors

    Two players form a symbol (rock, paper or scissors) with theirhands

    Rock crushes ScissorsScissors cut Paper

    Paper covers Rock

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    R k P S

    http://find/
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    Rock, Paper, Scissors

    Two players form a symbol (rock, paper or scissors) with theirhands

    Rock crushes ScissorsScissors cut Paper

    Paper covers Rock

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Prisoners DilemmaPublic Good GameRock, Paper, Scissors

    R k P S i

    http://find/
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    Rock, Paper, Scissors

    Two players form a symbol (rock, paper or scissors) with theirhands

    Rock crushes ScissorsScissors cut Paper

    Paper covers Rock

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    http://find/
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    Evolutionary Game

    Theory

    Why EGT?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Wh EGT?

    http://find/
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    Why EGT?

    Games can be played repeatedly, and also with a population ofplayers.

    Which populations/strategies are stable?

    Is it possible for mutants to invade a given population?

    How does cooperation arise and evolove?

    How does biodeversity emerge?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Wh EGT?

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Why EGT?

    Games can be played repeatedly, and also with a population ofplayers.

    Which populations/strategies are stable?

    Is it possible for mutants to invade a given population?

    How does cooperation arise and evolove?

    How does biodeversity emerge?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Wh EGT?

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    77/145

    Why EGT?

    Games can be played repeatedly, and also with a population ofplayers.

    Which populations/strategies are stable?

    Is it possible for mutants to invade a given population?

    How does cooperation arise and evolove?

    How does biodeversity emerge?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Why EGT?

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    78/145

    Why EGT?

    Games can be played repeatedly, and also with a population ofplayers.

    Which populations/strategies are stable?

    Is it possible for mutants to invade a given population?

    How does cooperation arise and evolove?

    How does biodeversity emerge?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Why EGT?

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    79/145

    Why EGT?

    Games can be played repeatedly, and also with a population ofplayers.

    Which populations/strategies are stable?

    Is it possible for mutants to invade a given population?

    How does cooperation arise and evolove?

    How does biodeversity emerge?

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    EGT New Concepts

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    EGT- New Concepts

    Evolutionary stable strategy (ESS)

    To investigate the stability of populations.Replicator dynamics

    To describe the evolution of different species within apopulation over time.

    Heiko Hotz A Short Introduction to Game Theory

    Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    EGT New Concepts

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    EGT- New Concepts

    Evolutionary stable strategy (ESS)

    To investigate the stability of populations.Replicator dynamics

    To describe the evolution of different species within apopulation over time.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    EGT- New Concepts

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    EGT- New Concepts

    Evolutionary stable strategy (ESS)

    To investigate the stability of populations.Replicator dynamics

    To describe the evolution of different species within apopulation over time.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    EGT- New Concepts

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    EGT New Concepts

    Evolutionary stable strategy (ESS)

    To investigate the stability of populations.Replicator dynamics

    To describe the evolution of different species within apopulation over time.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    84/145

    Evolutionary Game

    Theory

    Evolutionary Stable Strategy

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
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    Evolutionary Stable Strategy (ESS)

    An ESS is a strategy which, if adopted by a population,cannot be invaded by any competing alternative strategy.

    An equilibrium refinement to the Nash equilibrium.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
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    Evolutionary Stable Strategy (ESS)

    An ESS is a strategy which, if adopted by a population,cannot be invaded by any competing alternative strategy.

    An equilibrium refinement to the Nash equilibrium.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    y gy ( )

    Let E(, ) be the payoff for a player playing against aplayer playing .

    For to be an Nash equilibrium it is demanded:E(,) E(, )

    For to be an ESS it is demanded:1 E(, ) > E(, ) (equlibrium condition), or2

    E(, ) = E(, ) and E(,) > E(, ) (stability condition)

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
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    y gy ( )

    Let E(, ) be the payoff for a player playing against aplayer playing .

    For to be an Nash equilibrium it is demanded:E(,) E(, )

    For to be an ESS it is demanded:1 E(, ) > E(, ) (equlibrium condition), or2

    E(, ) = E(, ) and E(,) > E(, ) (stability condition)

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    y gy ( )

    Let E(, ) be the payoff for a player playing against aplayer playing .

    For to be an Nash equilibrium it is demanded:E(,) E(, )

    For to be an ESS it is demanded:1 E(, ) > E(, ) (equlibrium condition), or2

    E(, ) = E(, ) and E(,) > E(, ) (stability condition)

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
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    y gy ( )

    Let E(, ) be the payoff for a player playing against aplayer playing .

    For to be an Nash equilibrium it is demanded:E(,) E(, )

    For to be an ESS it is demanded:1 E(, ) > E(, ) (equlibrium condition), or2 E

    (, ) =E

    (, ) andE

    (,) >E

    (, ) (stability condition)

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Evolutionary Stable Strategy (ESS)

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    ( )

    Let E(, ) be the payoff for a player playing against aplayer playing .

    For to be an Nash equilibrium it is demanded:E(,) E(, )

    For to be an ESS it is demanded:1 E(, ) > E(, ) (equlibrium condition), or2 E

    (, ) =E

    (, ) andE

    (,) >E

    (, ) (stability condition)

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Evolutionary Game

    Theory

    Hawk-Dove Game

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Two individuals compete for a resource V.

    Each individual follows exactly one of two strategies describedbelow:

    Hawk: Initiate aggressive behaviour, not stopping until injuredor until ones opponent backs down.Dove: Retreat immediately if ones opponent initiatesaggressive behaviour.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
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    Two individuals compete for a resource V.

    Each individual follows exactly one of two strategies describedbelow:

    Hawk: Initiate aggressive behaviour, not stopping until injuredor until ones opponent backs down.Dove: Retreat immediately if ones opponent initiatesaggressive behaviour.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Two individuals compete for a resource V.

    Each individual follows exactly one of two strategies described

    below:Hawk: Initiate aggressive behaviour, not stopping until injuredor until ones opponent backs down.Dove: Retreat immediately if ones opponent initiatesaggressive behaviour.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Two individuals compete for a resource V.

    Each individual follows exactly one of two strategies described

    below:Hawk: Initiate aggressive behaviour, not stopping until injuredor until ones opponent backs down.Dove: Retreat immediately if ones opponent initiatesaggressive behaviour.

    Heiko Hotz A Short Introduction to Game Theory Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We assume

    whenever two individuals both initiate aggressive behaviour,conflict eventually results and the two individuals are equally

    likely to be injured,the cost of the conflict reduces individual fitness by someconstant value C,

    when a hawk meets a dove, the dove immediately retreats andthe hawk obtains the resource, and

    when two doves meet the resource is shared equally betweenthem.

    Heiko Hot A Short Introd ction to Game Theor Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
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    We assume

    whenever two individuals both initiate aggressive behaviour,conflict eventually results and the two individuals are equally

    likely to be injured,the cost of the conflict reduces individual fitness by someconstant value C,

    when a hawk meets a dove, the dove immediately retreats andthe hawk obtains the resource, and

    when two doves meet the resource is shared equally betweenthem.

    H ik H t A Sh t I t d ti t G Th Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We assume

    whenever two individuals both initiate aggressive behaviour,conflict eventually results and the two individuals are equally

    likely to be injured,the cost of the conflict reduces individual fitness by someconstant value C,

    when a hawk meets a dove, the dove immediately retreats andthe hawk obtains the resource, and

    when two doves meet the resource is shared equally betweenthem.

    H ik H t A Sh t I t d ti t G Th Introduction

    DefinitionsGames

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We assume

    whenever two individuals both initiate aggressive behaviour,conflict eventually results and the two individuals are equally

    likely to be injured,the cost of the conflict reduces individual fitness by someconstant value C,

    when a hawk meets a dove, the dove immediately retreats andthe hawk obtains the resource, and

    when two doves meet the resource is shared equally betweenthem.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We assume

    whenever two individuals both initiate aggressive behaviour,conflict eventually results and the two individuals are equally

    likely to be injured,the cost of the conflict reduces individual fitness by someconstant value C,

    when a hawk meets a dove, the dove immediately retreats andthe hawk obtains the resource, and

    when two doves meet the resource is shared equally betweenthem.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.

    But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.

    But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.

    But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    Hawk-Dove Game

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    This leads to the following payoff matrix:

    Hawk Dove

    Hawk 12 (V C),12 (V C) V, 0

    Dove 0,V V/2,V/2

    Dove is no stable strategy, sinceV2 = E(D,D) < E(H,D) = V.

    Because of E(H,H) = 12 (V C) and E(D,H) = 0, H is an

    ESS if V C.But what if V < C?

    Neither H nor D is an ESS.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Evolutionary Game

    Theory

    The Replicator Dynamics

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Let us consider now a population consisting of n types, andlet xi(t) be the frequency of type i at some time t.

    The state of the population is given by the vector

    x(t) = x1(t), . . . , xn(t).The state of the population will change, since some specieswill get higher payoffs and will reproduce better than others,or others adopt the strategy of the species with the betterfitness.

    We want to postulate a law of motion for x(t), i.e. we wantto investigate the evolution of the different species over time.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Let us consider now a population consisting of n types, andlet xi(t) be the frequency of type i at some time t.

    The state of the population is given by the vector

    x(t) = x1(t), . . . , xn(t).The state of the population will change, since some specieswill get higher payoffs and will reproduce better than others,or others adopt the strategy of the species with the betterfitness.

    We want to postulate a law of motion for x(t), i.e. we wantto investigate the evolution of the different species over time.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    111/145

    Let us consider now a population consisting of n types, andlet xi(t) be the frequency of type i at some time t.

    The state of the population is given by the vector

    x(t) = x1(t), . . . , xn(t).The state of the population will change, since some specieswill get higher payoffs and will reproduce better than others,or others adopt the strategy of the species with the betterfitness.

    We want to postulate a law of motion for x(t), i.e. we wantto investigate the evolution of the different species over time.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    112/145

    Let us consider now a population consisting of n types, andlet xi(t) be the frequency of type i at some time t.

    The state of the population is given by the vector

    x(t) = x1(t), . . . , xn(t).The state of the population will change, since some specieswill get higher payoffs and will reproduce better than others,or others adopt the strategy of the species with the betterfitness.

    We want to postulate a law of motion for x(t), i.e. we wantto investigate the evolution of the different species over time.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    If individuals meet randomly and then engage in a symmetricgame with payoff matrix A, then (Ax)i is the expected payoff

    for an individual of type ixTAx is the average payoff in the population state x.

    The evolution of x over time is described by the replicatorequation:

    xi = xi[(Ax)i xTAx]

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    If individuals meet randomly and then engage in a symmetricgame with payoff matrix A, then (Ax)i is the expected payoff

    for an individual of type ixTAx is the average payoff in the population state x.

    The evolution of x over time is described by the replicatorequation:

    xi = xi[(Ax)i xTAx]

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    If individuals meet randomly and then engage in a symmetricgame with payoff matrix A, then (Ax)i is the expected payoff

    for an individual of type ixTAx is the average payoff in the population state x.

    The evolution of x over time is described by the replicatorequation:

    xi = xi[(Ax)i xTAx]

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    By setting xi = 0, we obtain the evolutionary stable states ofa population.

    A population is said to be in an evolutionarily stable state if

    its genetic composition is restored by selection after adisturbance, provided the disturbance is not too large.

    For V > C, the only evolutionary stable state is a populationconsisting of hawks.

    For V < C, a mixed population with a fraction V/C of hawksand a fraction 1 V/C of doves is evolutionary stable.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    By setting xi = 0, we obtain the evolutionary stable states ofa population.

    A population is said to be in an evolutionarily stable state if

    its genetic composition is restored by selection after adisturbance, provided the disturbance is not too large.

    For V > C, the only evolutionary stable state is a populationconsisting of hawks.

    For V < C, a mixed population with a fraction V/C of hawksand a fraction 1 V/C of doves is evolutionary stable.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    118/145

    By setting xi = 0, we obtain the evolutionary stable states ofa population.

    A population is said to be in an evolutionarily stable state if

    its genetic composition is restored by selection after adisturbance, provided the disturbance is not too large.

    For V > C, the only evolutionary stable state is a populationconsisting of hawks.

    For V < C, a mixed population with a fraction V/C of hawksand a fraction 1 V/C of doves is evolutionary stable.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Why EGT?

    Evolutionary Stable Strategy (ESS)Hawk-Dove GameThe Replicator Dynamics

    The Replicator Dynamics

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    119/145

    By setting xi = 0, we obtain the evolutionary stable states ofa population.

    A population is said to be in an evolutionarily stable state if

    its genetic composition is restored by selection after adisturbance, provided the disturbance is not too large.

    For V > C, the only evolutionary stable state is a populationconsisting of hawks.

    For V < C, a mixed population with a fraction V/C of hawksand a fraction 1 V/C of doves is evolutionary stable.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Applications

    Evolution of Cooperation

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/http://goback/
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    We have seen, that the logical move in the PrisonersDilemma is to defect

    Consider spatially structured populations

    Limited local interactions enable cooperators to form clusters

    Individuals can outweigh their losses against defectors by gainsfrom interactions within the cluster.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We have seen, that the logical move in the PrisonersDilemma is to defect

    Consider spatially structured populations

    Limited local interactions enable cooperators to form clusters

    Individuals can outweigh their losses against defectors by gainsfrom interactions within the cluster.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    123/145

    We have seen, that the logical move in the PrisonersDilemma is to defect

    Consider spatially structured populations

    Limited local interactions enable cooperators to form clusters

    Individuals can outweigh their losses against defectors by gainsfrom interactions within the cluster.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    We have seen, that the logical move in the PrisonersDilemma is to defect

    Consider spatially structured populations

    Limited local interactions enable cooperators to form clusters

    Individuals can outweigh their losses against defectors by gainsfrom interactions within the cluster.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Example revealed critical phase transitions.

    This falls into the universality class of directed percolation onsquare lattices.

    Results for different population structures in the PD arediscussed and related to condensed matter physics.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
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    Example revealed critical phase transitions.

    This falls into the universality class of directed percolation onsquare lattices.

    Results for different population structures in the PD arediscussed and related to condensed matter physics.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Evolution of Cooperation

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Example revealed critical phase transitions.

    This falls into the universality class of directed percolation onsquare lattices.

    Results for different population structures in the PD arediscussed and related to condensed matter physics.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Applications

    Biodiversity

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    One of the central aims of ecology is to identify mechanismsthat maintain biodiversity.

    Theoretical models have shown that competing species cancoexist if ecological processes such as dispersal, movement,and interaction occur over small spatial scales.

    In particular, this may be the case for nontransitivecommunities, that is, those without strict competitive

    hierarchies.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    One of the central aims of ecology is to identify mechanismsthat maintain biodiversity.

    Theoretical models have shown that competing species cancoexist if ecological processes such as dispersal, movement,and interaction occur over small spatial scales.

    In particular, this may be the case for nontransitivecommunities, that is, those without strict competitive

    hierarchies.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    One of the central aims of ecology is to identify mechanismsthat maintain biodiversity.

    Theoretical models have shown that competing species cancoexist if ecological processes such as dispersal, movement,and interaction occur over small spatial scales.

    In particular, this may be the case for nontransitivecommunities, that is, those without strict competitive

    hierarchies.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)Applications

    Outlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
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    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    134/145

    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/http://goback/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    135/145

    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    136/145

    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    137/145

    There exist three strains of Escherichia coli bacteria.

    Type A releases toxic colicin and produces, for its ownprotection, an immunity protein.

    Type B produces the immunity protein only.

    Type C produces neither toxin nor immunity.

    The production of the toxic colicin and the immunity proteincauses some higher costs.

    Thus B beats A, C beats B and A beats C.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Evolution of CooperationBiodiversity

    Biodiversity

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    green: resistant strainred: colicin producing strainblue: sensitive strain

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Outlook

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Outlook

    http://find/
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    Most evolutionary game dynamics have been studied in thecontext of infinitely large populations. We expect that finitepopulation size effects will lead to surprising outcomes and

    might question the importance of traditional evolutionarystability.

    Emerging fields as diverse as metabolic control networkswithin cells and evolutionary psychology, for example, should

    benefit from game theory.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Outlook

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    141/145

    Most evolutionary game dynamics have been studied in thecontext of infinitely large populations. We expect that finitepopulation size effects will lead to surprising outcomes and

    might question the importance of traditional evolutionarystability.

    Emerging fields as diverse as metabolic control networkswithin cells and evolutionary psychology, for example, should

    benefit from game theory.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    GamesEvolutionary Game Theory (EGT)

    ApplicationsOutlook

    Outlook

    C lt al i te etatio s of e licato d a ics ofte ass e

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

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    Cultural interpretations of replicator dynamics often assumethat successful strategies spread by imitation or learning, butthe learning of complicated strategies from behavioralobservations is a nontrivial task that needs specific

    investigation.

    Interactions among genes, viruses, cells, and humans are ofteninstances of evolutionary games that are amenable toempirical and theoretical investigation.

    Game theory is the appropriate tool whenever the success ofan individual depends on others.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    Games

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Outlook

    Cultural interpretations of replicator dynamics often assume

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    143/145

    Cultural interpretations of replicator dynamics often assumethat successful strategies spread by imitation or learning, butthe learning of complicated strategies from behavioralobservations is a nontrivial task that needs specific

    investigation.

    Interactions among genes, viruses, cells, and humans are ofteninstances of evolutionary games that are amenable toempirical and theoretical investigation.

    Game theory is the appropriate tool whenever the success ofan individual depends on others.

    Heiko Hotz A Short Introduction to Game Theory

    IntroductionDefinitions

    Games

    Evolutionary Game Theory (EGT)Applications

    Outlook

    Outlook

    Cultural interpretations of replicator dynamics often assume

    http://find/
  • 7/28/2019 Heiko Hotz Spieltheorie Vortrag

    144/145

    Cultural interpretations of replicator dynamics often assumethat successful strategies spread by imitation or learning, butthe learning of complicated strategies from behavioralobservations is a nontrivial task that needs specific

    investigation.Interactions among genes, viruses, cells, and humans are ofteninstances of evolutionary games