Solutions to Chapter 2 Exercises

S1. (a) Assuming a sufficient supply of yogurt is available for all shoppers, each shopper is simply making a decision. If some flavors of yogurt were in short supply, then it would be a game, because shoppers could, for example, make sure to arrive at the store early in order to get their preferred selections. (b) Again, probably not an interaction between mutually aware players. (There may be a strategic component to dress choice if the girls are aware that each is buying one and if there is some benefit to being different from the others.) (c) For a college senior, the choice here is a decision, unless you argue that a game is being played with the student’s future self. (d) This is a strategic interaction between mutually aware rival firms. (e) The choice of running mate is a game played between different presidential candidates looking forward to the payoffs of votes in an upcoming election. S2. (a) (i) Simultaneous play; (ii) zero-sum; (iii) can be repeated, although description is of a single play; (iv) symmetric imperfect information (neither player has information about the action being taken by the other); (v) fixed rules; (vi) cooperative agreements are unlikely. (b) (i) Sequential play; (ii) non-zero-sum game for voters; (iii) usually not repeated (though some bills may face multiple votes); (iv) full information; (v) fixed rules; (vi) party apparatus may provide mechanism for cooperation among members of the same party or even between parties. (c) (i) Simultaneous play; (ii) non-zero-sum; (iii) not repeated; (iv) imperfect information; (v) fixed rules; (vi) noncooperative.