10/20/03
11
Analysis of Some Simple
Strategies
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Three simple strategies:
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ALL-D
: always defect
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ALL-C
: always cooperate
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RAND
: randomly cooperate/defect
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Effectiveness depends on environment
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ALL-D
optimizes local (individual) fitness
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ALL-C
optimizes global (population) fitness
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RAND
compromises
ALL-D: the safest strategy; cannot be beat or exploited; good at exploiting;
does poorly against self or nasty strategies
thus it optimizes local (own) fitness at expense of population
ALL-C: does well when interacting with self or other nice strategies
endlessly exploited by ALL-D and other nasty strategies
RAND: a compromise
somewhat resistant to exploitation
can occasionally exploit others
does reasonably well against self