1. Game 2 Dominant Strategies
Game Theory
Game 2
Dominant Strategies

2. The Game The Economist S G Time 0 , 50 100 , 80 60 , 0 60 , 100
0 , 50
100 , 80
60 , 0
60 , 100
Mike Shor

3. The Game G is “safe” for Time
S is better for Time if the Economist is likely to pick G
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Mike Shor

4. The Economist In the role of The Economist:
89% selected G (all but two)
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Mike Shor

5. Time In the role of Time: Only 32% selected S The Economist S G Time
0 , 50
100 , 80
60 , 0
60 , 100
Mike Shor

6. Rationality & Common Knowledge
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Rationality:
If you have a dominant strategy, play it
Doesn’t matter what opponent might do!
Mike Shor

7. Rationality & Common Knowledge
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Common Knowledge:
Others will use their dominant strategy
89% did!
But …
Mike Shor

8. Rationality & Common Knowledge
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Common Knowledge:
Others will use their dominant strategy
(usually)
Tyler earned 0
Mike Shor

9. Rationality & Common Knowledge
The Economist S G
Time
0 , 50
100 , 80
60 , 0
60 , 100
Common Knowledge:
Others will use their dominant strategy
(usually)
Tony earned 0
Mike Shor

10. Why Play a Dominated Strategy?
0 , 50
100 , 80
60 , 0
60 , 100
“I am in competition”
“I am taking someone down with me”
“I lose 30, but they lose 100”
“Huh? I was confused”
Mike Shor

11. Historical Data Rationality (Economist editors)
Vanderbilt: 90% pick Grenada
Rutgers: 92% pick Grenada
UConn: 92% pick Grenada
Common Knowledge (Time editors)
Vanderbilt: 56% pick Scandal
Rutgers: 56% pick Scandal
UConn: 46% pick Scandal
Mike Shor

12. Future Data
Mike Shor