An Answer for the Self-test on Mixed Strategies

                                 Forehand      Backhand
                Forehand            9,1         0,10
                Backhand           0,10         6,4

This game is like the Tennis Game in Dixit and Nalebuff, except that if the Receiver is surprised, he never succeeds in returning the serve.

1_1 What is the Nash equilibrium probability of Forehand for the Server?
A. Between 0 and .2, inclusive.
B. Greater than .2 but less than .5.
C. Between .5 and .7, inclusive
D. Greater than .7

C. Try again. If the Server chooses such a high probability of Forehand, the Receiver can advantage of that by choosing Forehand all the time.

If the server chooses the a probability of .5, then

Receiver's Payoff (Forehand) = .5 (9) + .5(0) = 4.5 > Receiver's Payoff (Backhand) =.5(0) + .5 (6) = 3.

To get the correct answer, you need to choose a mixing probability X for the Server such that the Receiver does no better from Forehand than from Backhand. To do that, you solve

Receiver's Payoff (Forehand) =X (9) + (1-X)(0) = Receiver's Payoff (Backhand) =X(0) + (1-X) (6).

Return to Self Test 2.

Send comments to Prof. Rasmusen. Last updated: December 2, 1996