Now suppose that Mr. Ward does not vote. Again, the possible payoffs are determined by the
“strategy” that Mrs. Ward chooses. If she chooses to vote (bottom left-hand cell), she gains 24
units of utility, incurs the cost of voting of 12 units of utility, and does not suffer the loss of
utility from a potential vote for the opposition. Thus, Mrs. Ward's payoff from this outcome
is 24−12=1224−12=12. At the same time, Mr. Ward receives a payoff of –24 units of utility,
since Mrs. Ward has voted for the opposition and Mr. Ward has not gained any utility from
voting, nor incurred the cost of voting.
Again, assume that Mr. Ward does not vote. If Mrs. Ward does not vote either (bottom right-hand
cell), then neither spouse receives any utility from voting or incurs any cost of voting. Since
neither has voted for the opposition party, no loss of utility is suffered either. Thus, the payoff for
both spouses is 0.