PPS55: Spring 2008
Problem Set #2 - ANSWERS
Larry King is planning to invite Mitt Romney, Hilary Clinton and Dennis Kucinich to come on
his show and talk about their platforms.
For complicated reasons involving career advancement,
reputation of ones’ party, and personal feelings about the individuals involved, let’s assume that
the payoffs are those depicted on the following game tree:
Suppose that Larry will sequentially invite Romney, then Clinton, then Kucinich.
should Romney do?
Show your work!!!
Romney should accept. Note that to solve a sequential game we use backwards induction, so you simply
prune the tree from right to left, determining what an individual would do if faced with that choice. Thus
strategies like maximin that one might use in a simultaneous game are completely irrelevant. Each party
knows exactly where they are in the tree when they make their choice, and can see what the others will do
once their choice is made.
For a similar reason the idea of a dominant strategy is also irrelevant in a
Would it make a difference if Clinton could commit to accepting or declining before Romney
makes his choice?
Briefly explain why or why not.
If Clinton commits before Romney
4, 4, 5
6, 3, 1
3, 1, 7
1, 2, 3
2, 6, 6
7, 7, 2
5, 5, 8
8, 8, 4