Game Theory Overview
Applicable to varied situations, from daily interactions to strategic decision-making in business (e.g. pricing, quality decisions).
Focus on a duopoly (two firms) vs. a monopoly (one firm).
Example: Pricing Strategies of Two Theaters
Firms: Premier and Cinemark, both showing the same movies.
Strategies: Each can set ticket prices at $5 or $10.
Payoff Matrix:
Both charge $5 → Each earns $1,000,000 profit.
Cinemark charges $10 → Premier earns $2,000,000, Cinemark earns $500,000.
Premier charges $10 → Cinemark earns $2,000,000, Premier earns $500,000.
Both charge $10 → Each earns $1,500,000.
Total Profit Analysis:
Highest total profit occurs at $10 ($3,000,000).
Prisoner's dilemma structure identified.
Nash Equilibrium
Cinemark’s Dominant Strategy: Always set price at $5 regardless of Premier’s decision.
If Premier charges $5: Moving to $10 reduces profit from $1,000,000 to $500,000.
If Premier charges $10: Moving from $5 to $10 reduces profit from $2,000,000 to $1,500,000.
Premier’s Dominant Strategy: Same logic applies, leading to Nash Equilibrium at pricing of $5.
Both firms earn $1,000,000 each.
Cooperation (collusion) could lead to higher profits ($1,500,000), illustrating competition's consumer benefit.
Collusion and Competition
Collusion is often illegal and hard to sustain due to prisoner's dilemma conflicts.
Communication and repetition can help overcome these dilemmas.
Sequential Decision-Making: Quality/Niche Example
Firms: "Original" (moves first) vs. "Newcomer" (moves second).
Choices: High-end vs. Discount clothing.
Payoffs:
Both high-end → $10,000,000 each.
Original high-end, Newcomer discount → Original earns $20,000,000, Newcomer earns $12,000,000.
Original discount, Newcomer high-end → Original earns $12,000,000, Newcomer earns $20,000,000.
Both discount → $6,000,000 each.
Backward Induction:
Newcomer will choose discount if Original occupies high-end (earn $12,000,000 vs. $10,000,000).
If Original does discount, Newcomer prefers high-end (earning $20,000,000 over $6,000,000).
Outcome:
Original produces high-end (earning $20,000,000), Newcomer produces discount (earning $12,000,000).
Market Dynamics
Original has a first-mover advantage, influencing Newcomer’s choice.
Resulting Nash Equilibrium: Original: high-end, Newcomer: discount.
Conclusion
Game theory applications extend beyond simple examples to complex market scenarios (product differentiation, fixed costs).
Encourages rigorous decision-making in both personal and business contexts.