In repeated interaction a strategy that cooperates first, then mirrors the other side, performs robustly against sophisticated rivals.
Axelrod's 1980 tournaments. Tit-for-tat won twice against far more sophisticated entries, and its properties are nice, retaliatory, forgiving and clear — the forgiveness is what beats grim trigger.
In practice
- A supplier late once is warned once, delivers on time thereafter, and the relationship survives what a permanent penalty would have ended.
- Two departments that alternate covering each other's shortfalls keep it up for years, and the first to stop is copied within a month.
- Further reading
- Wikipedia
- Subject
- Games & Strategic Interaction
- Essay
- The recurring shapes of conflict and cooperation