Game Theory and Giuliani

The Evangelical Outpost uses game theory to demonstrate that moderate Republicans who support Giuliani in the primary will be responsible for electing Hillary Clinton, not conservative Republicans who stay home in November:

Imagine that you have three groups of voters. Group A likes Hillary and opposes all Republican nominees; Group B prefers Giuliani, but would choose another nominee over Hillary; Group C prefers anyone other than Giuliani and Hillary….

Group A would be happy with A1, and unhappy with either A2 or A3. Similarly, Group B would be unhappiest with B1, happy with B2, and satisfied with B3. Group C would be unhappy with C1, dissatisfied with C2, and happy with C3.

Now let’s examine what rational choices each group of voters should make in a Republican primary.

Since the GOP is never going to nominate Hillary, the most rational choice for Group A would be to skip the Republican primary altogether and vote in the Democratic primaries. The most rational choice for Group C would be C3–anyone other than Giuliani. So what should Group B choose? Even though their first preference is B2, they have to consider how Group C will vote.

For Group B, choice B3 is what game theorists call the minimax condition, the choice which minimizes the maximum possible loss. They don’t get Giuliani but they don’t get Hillary either. (That same outcome, by the way, is the optimum choice for Group C.)

Even if they were unable to communicate with Group C, the most rational choice for Group B would be to choose the minimax. But they have even more incentive because social conservatives (Group C) have communicated to Giuliani supporters (Group B) that they will not accept option C2. All things being equal, it would therefore be irrational for primary voters to choose Giuliani….

Unless social conservatives vote for Hillary in either the primaries or the general election, we are in no way to blame for her moving back into the White House. That blame will go to our friends and neighbors. The same goes for the nomination of Rudy.

But what if the reason that Hillary wins is, as some want to claim, because social conservatives did not choose the lesser of two evils and vote for Rudy? Again, we social conservatives are not to blame at all. We are the ones who will have made the rational choice during the primaries while the Giuliani supporters made an irrational choice.

This is a solid explanation of the inherent futility of the moderate Republican candidate, one that I wish I had thought to develop. As I’ve been pointing out for months now, it is counterproductive to nominate a candidate who is so moderate that he has negative appeal to the base. The polls are irrelevant, Giuliani and Romney are demonstrably less electable than Paul, Huckabee or Thompson. Thompson and Huckabee can’t beat Clinton because they share her views on the major issues of the election cycle, but that’s another matter entirely.

By the way, Richard Dawkins should note that this is a proper use of game theory, not inventing Evolutionary Stable Strategies out of arbitrary assumptions and imaginary values.