Player 1 Cooperate (C) Defect (D) Cooperate (C) 3,3 8,0 Player 2 Defect (D) 0,8 1,1 In general, a combination of strategies is a Nash equilibrium if ... Every player is choosing a best response against the other players' strategies. Every player has a positive payoff. The players maximize the sum of their payoffs. The players choose identical strategies. If the game is repeated, which cooperative actions could benefit both players? Both players choose C. Player 1 chooses C, Player 2 chooses D. Player 1 chooses D, Player 2 chooses C. Both players choose D.

Problem 2. Consider the partnership-game we discussed in Lecture 3 (pages 81-87 of the textbook). Now change the setup of the game so that player 1 chooses x = [0, 4], and after observing the choice of x, player 2 chooses y ≤ [0, 4]. The payoffs are the same as before. (a) Find all SPNE (subgame perfect Nash equilibria) in pure strategies. (b) Can you find a Nash equilibrium, with player 1 choosing x = 1, that is not subgame perfect? Explain.

Tyler and Pam are arrested and charged with armed robbery. The police interview both suspects separately about their involvement in the crime. Each suspect has to make a decision. They can betray the other suspect by confessing that they both committed the crime, or they can cooperate with the other suspect by remaining silent. The table shows the sentences that Tyler and Pam will receive given their choices. Use the table to answer the question. What will be the dominant strategy outcome for Tyler and Pam? They both get 10 years. Pam gets 5 years, and Tyler gets 15 years. O They both get 12 years. O Tyler gets 5 years, and Pam gets 15 years. Tyler Stay silent Confess Stay silent Pam gets 10 years Tyler gets 10 years Pam gets 15 years Pam Tyler gets 5 years Confess Pam gets 5 years Tyler gets 15 years Pam gets 12 years Tyler gets 12 years

Finding Nash Equilibria Consider the following two player, normal form game: Player 1 Player 2 C L (2,1) U M (-2,-2) D R (2, -1) (1,2) (-1, 1) (0,0) (3,1) (0,0) (-1,-1) Find all pure and mixed strategy Nash equilibria. Calculate each player's expected payoffs at each equilibrium.

An auditor and a taxpayer play the following strategic game. The auditor must choose whether to Audit (A) the taxpayer or not (N). The taxpayer independently decides whether to be Honest (H) in reporting her income or to Cheat (C). Since auditing is costly, the auditor prefers not to audit the taxpayer if she reports honestly, but prefers to audit if the axpayer cheats. If the taxpayer is caught cheating (i.e. if she cheats and is audited), then she receives a severe punishment. If she is not caught, she prefers cheating to being honest. Suppose that payoffs are as in the following matrix: Auditor Taxpayer C 4, -10 0,4 H A 2,0 N 4,0 (a) Find all (mixed strategy) Nash equilibria of this game. Solution: There is no NE in pure strategies. Moreover, since each pure strategy has a unique best response, there is no NE in which either player plays a pure strategy. If the Auditor chooses A with probability p and the Taxpayer chooses H with probability q, then the condition for the Auditor to…

1.a) If the three executives of a fraudulent organization report nothing to the authorities, each gets a payoff of 100. If at least one of them blows the whistle, then those who reported the fraud get 28, while those who didn’t get -100. Suppose they play a symmetric mixed-strategy Nash equilibrium where each is silent (does not report fraud) with probability p. What is p?A, 0.1B, 0.28C, 0.5D, 0.8 b) In a two-player game, with strategies and (some known and some unknown) payoffs as shown below, suppose a mixed-strategy equilibrium exists where 1 plays C with probability 3/4, and Player 2 randomizes over X, Y, and Z with equal probabilities.   What are the pure-strategy equilibria of this game?      A, (A, Y) and (B, X)B, (A, Z) and (C, Y)C, (B, X) and (C, X)D, (C, X) and (C, Y)

Keith and Blake play a simultaneous one-shot game. Keith chooses between Top and Bottom, whereas Blake chooses between left and right. Payoffs are given by (Keith's payoffs are listed first and Blake's payoffs second): Top+left: 3,-6. Top+right:0,-7 Bottom+left:4,0. Bottom+right:-2,6. In a mixed strategy equilibria, Keith will play Top with what probability? 1. 6/7 2. 1/4 3. 1/2 4.  1/7 5. 0 6. 3/4

In a small town there are two pizza restaurants . If neither restaurant advertises, its revenue will not change. If only one firm advertises, the firm that advertises will double its revenue and the firm that doesn't advertise will see a decrease in its revenue, but if both firms advertise, their revenue will not change. What outcome would be predicted by game theory in this market? Both restaurants will advertise. Game theory would predict chat sometimes one restaurant would advertise, and the rest of the time both will advertise. Neither restaurant will advertise Game theory is only a theory and cannot predict real-world events. One restaurant will advertise.