Grade Distribution, Test 1
70
60
Average: 80.3
50
40
30
20
10
96
91
86
81
76
71
66
61
55
50
0
The Prisoners’ Dilemma and the
Liberal Tragedy
Lecture 9
The Liberal Vision: International
Politics as Tragedy
• All Countries Lose From War.
• Therefore, All Countries Would Gain If All
Would Prepare Less for and Engage in
Fewer Wars.
• Tragedy: Even Peace-loving Countries Are
Forced to Militarize by the Anarchic
Structure of the International System.
The Prisoners’ Dilemma
• The Liberal Tragedy Arises From Strategic
Interaction.
• The Prisoners’ Dilemma Is the Game We
Will Use to Model this Interaction.
• The Prisoners’ Dilemma is a General Model
of Cooperation.
– Between Individuals
– Between Governments
The Elements of a Game
• The Actors: Who Is Playing?
• Actors’ Strategies: What Choices Do The Actors
Have?
• Outcomes: What Are the Results of the
Interactive Choices Actors Make?
• Preference Orders: How Do the Actors Rank All
of the Possible Outcomes?
• The Solution: How will Each Actor Play the
Game, Given the Strategies, Outcomes, and
Preference Orders?
The India-Pakistan Nuclear
Game
• The Actors: Pakistan and India
• The Strategies: Two Choices
– Build Nuclear Weapons
– Don’t Build Nuclear Weapons
• The 4 Possible Outcomes:
–
–
–
–
Arms Race: Both Build Nuclear Weapons
Stable Military Balance: Neither Builds N. Weapons
Pakistan Advantage: Pakistan Builds, India Doesn’t
India Advantage: India Builds, Pakistan Doesn’t
• For Preference Orders….
The Prisoners’ Dilemma
India
Don’t Build
Build
Stable Balance
India Advantage
Pakistan Advantage
Arms Race
Don’t Build
Pakistan
Build
Preference Orders:
India: India Advantage > Stable Balance > Arms Race > Pakistan Advantage
Pakistan: Pakistan Advantage > Stable Balance > Arms Race > India Advantage
The India-Pakistan Game, Again
India
Don’t Build
Build
Don’t
Build
Stable Balance
(3, 3)
India Advantage
(1, 4)
Build
Pakistan Advantage
(4, 1)
Arms Race
(2,2)
Pakistan
Solving the Game: Backwards Induction
build
2,2 (Arms Race)
Pakistan
build
don’t build
4,1 (India Advantage)
India
build
1,4 (Pakistan Advantage)
don’t build
Pakistan
don’t build
3,3 (Stable Balance)
The Prisoners’ Dilemma, Again
Dominant Strategy
Pareto Optimal
India
Don’t Build
Build
Don’t Build
3, 3
1, 4
Build
4, 1
2,2
Pakistan
Dominant
Strategy
Nash Equilibrium
Other Examples of the Logic of
the Prisoners’ Dilemma
• Current Struggle Between Israelis and
Palestinians.
– Strategies: Retaliate; Turn the Other Cheek
• France and Germany Following WWI.
– Strategies: Re-Arm; Don’t Re-Arm
• United States and Iraq
– Strategies:
• US: Pursue Objectives Through Inspections Regime OR Use
Force to Overthrow Regime
• IRAQ: Allow Inspections in Compliance with UN Security
Council Resolutions OR Refuse to Cooperate
• Military Force is a “Rational” Strategy for Both
Parties In All of These Conflicts.
Broader Importance of the
Prisoners’ Dilemma
• Tragedy of International Politics: Both Can Be
Better Off, but Unable to Realize These Joint
Gains.
• Inability to Realize Joint Gains Arises From
Inability to Make Binding Commitments.
• If Agreements Could Be Concluded and Enforced,
Then Joint Gains Could Be Realized.
• The Absence of an Enforcement Mechanism—
Anarchy—Is the Source of Tragedy.
• Change the Institutional Framework, Change
International Politics.
Is There a Way to Escape The Dilemma?
• Iterated Play Repeated Play of
the Game Without a Known
End Point.
• Tit-For-Tat Strategies
Decentralized Enforcement
Mechanism.
• Alters Calculation of Payoffs
– Single Play: One Time
Payoff
– Repeated Play: Stream of
Payoffs Over Time
– Stream of Payoffs > One
Time Payoff
• Becomes Rational To Play a
Cooperative Strategy
• International Organizations
Help Promote Transformation.
• Provide Rule-Based Structure
for Interaction.
– Transparency
• Provide High Quality and
Potentially Unbiased
Information About Behavior of
Others.
– De-Politicize Monitoring
• Help Ensure that Retaliation/
Enforcement is Proportional.
– Prevent Vicious Cycles