4. Consider the Prisoner's Dilemma in general form, repeated infinitely: B Cooperate Defect A Cooperate C,C L,H Defect H,L D,D where, to make this a Prisoner's Dilemma, H > C > D > L. (a) Imagine, all else constant, C increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (b) Imagine, all else constant, L increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (c) Imagine, all else constant, D increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (d) If two players with different personal values for r play, will the player with the higher r be more or less likely to cooperate when facing a Grim Trigger player? Explain (assume the players are otherwise the same).

4. Consider the Prisoner's Dilemma in general form, repeated infinitely: B Cooperate Defect Cooperate C,C L. H Defect H.L D,D where, to make this a Prisoner's Dilemma, H > C > D > L. (a) Imagine, all else constant, C increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (b) Imagine, all else constant, L increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (c) Imagine, all else constant, D increases. Will this make players more or less likely to cooperate when facing a Grim Trigger player? Explain. (d) If two players with different personal values for r play, will the player with the higher r be more or less likely to cooperate when facing a Grim Trigger player? Explain (assume the players are otherwise the same)