Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory...

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Game Theory Mechanism Design Game Theory and Mechanism Design Jeff Jacobs Stanford University [email protected] November 2, 2013 1 / 26

Transcript of Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory...

Page 1: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Game Theory and Mechanism Design

Jeff Jacobs

Stanford University

[email protected]

November 2, 2013

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Page 2: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Sad (and happy!) introduction

Invented by von Neumann and Morgenstern in 1945

Not related to video games

:(

Can be used to analyze video games!

:)

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Page 3: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Sad (and happy!) introduction

Invented by von Neumann and Morgenstern in 1945

Not related to video games

:(

Can be used to analyze video games!

:)

3 / 26

Page 4: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Sad (and happy!) introduction

Invented by von Neumann and Morgenstern in 1945

Not related to video games

:(

Can be used to analyze video games!

:)

4 / 26

Page 5: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Sad (and happy!) introduction

Invented by von Neumann and Morgenstern in 1945

Not related to video games

:(

Can be used to analyze video games!

:)

5 / 26

Page 6: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Sad (and happy!) introduction

Invented by von Neumann and Morgenstern in 1945

Not related to video games

:(

Can be used to analyze video games!

:)

6 / 26

Page 7: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Your First Game: Rock, Paper, Scissors

Rock Paper Scissors

Rock 0, 0 −1, 1 1,−1

Paper 1,−1 0, 0 −1, 1

Scissors −1, 1 1,−1 0, 0

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Page 8: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 9: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 10: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 11: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent ConfessStay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 12: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent ConfessStay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 13: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0

Confess 0,−10 −3,−3

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Page 14: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0Confess 0,−10 −3,−3

14 / 26

Page 15: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0Confess 0,−10 −3,−3

15 / 26

Page 16: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0Confess 0,−10 −3,−3

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Page 17: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent Confess

Stay Silent −1,−1 −10, 0Confess 0,−10 −3,−3

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Page 18: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Nash Equilibrium: Prisoners’ Dilemma

Stay Silent ConfessStay Silent −1,−1 −10, 0Confess 0,−10 −3,−3

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Page 19: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Why is Nash Equilibria Important?

Nash’s Theorem (Nash, 1951)

Every game with a finite number of players and actions has at leastone Nash equilibrium.

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Page 20: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

What is Mechanism Design?

We get to design a game

We want the game to have a certain outcome

Let’s design it so that the outcome we want is a Nashequilibrium!

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Page 21: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

Auctions

We have a good g that we want to sell

We have n bidders, each of whom has a valuation vi for thegood

They submit their bids bi in sealed envelopes

Who do we give the item to?

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Page 22: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

The Vickrey Auction

Instead of giving to the highest bidder for their bid, give tothe highest bidder for the second highest bid.

Claim: Vickrey auction induces an honest bidding Nashequilibrium.

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Page 23: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

The Vickrey Auction

Thought Experiment 1: What happens if I bid lower than myvalue?

Thought Experiment 2: What happens if I bid higher than myvalue?

Conclusion: Honest bidding is a Nash equilibrium!

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Page 24: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

The Vickrey Auction

Thought Experiment 1: What happens if I bid lower than myvalue?

Thought Experiment 2: What happens if I bid higher than myvalue?

Conclusion: Honest bidding is a Nash equilibrium!

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Page 25: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

The Vickrey Auction

Thought Experiment 1: What happens if I bid lower than myvalue?

Thought Experiment 2: What happens if I bid higher than myvalue?

Conclusion: Honest bidding is a Nash equilibrium!

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Page 26: Game Theory and Mechanism Design - Stanford University … · 2013. 11. 2. · Game Theory Mechanism Design The Vickrey Auction Instead of giving to the highest bidder for their bid,

Game Theory Mechanism Design

The End

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