The changed payoff matrix makes this unlike the Prisoner’s Dilemma even without the addition of communication; more like a restricted bargaining game. One noteworthy difference from the Prisoner’s Dilemma is that this game lacks a pure Nash equilibrium.
The usual definition of Nash equilibrium requires only ≤, not <, so Defect-Defect, Cooperate-Defect and Defect-Cooperate are Nash equilibria (and pure) but not “strong” Nash equilibria. You want this definition, because games need not have strong Nash equilibria, even if you allow mixed strategies.
(Apparently the game is called “weak prisoner’s dilemma” in the literature).
The changed payoff matrix makes this unlike the Prisoner’s Dilemma even without the addition of communication; more like a restricted bargaining game. One noteworthy difference from the Prisoner’s Dilemma is that this game lacks a pure Nash equilibrium.
Edit: Apparently not quite; see below.
The usual definition of Nash equilibrium requires only ≤, not <, so Defect-Defect, Cooperate-Defect and Defect-Cooperate are Nash equilibria (and pure) but not “strong” Nash equilibria. You want this definition, because games need not have strong Nash equilibria, even if you allow mixed strategies.
(Apparently the game is called “weak prisoner’s dilemma” in the literature).
Oops, didn’t realize that.