Virginia Postrel’s God and the Electorate opens with an unusual hypothesis:
Have religious issues become more important in politics because too few Americans go to church?That is the surprising suggestion of a new working paper by the Harvard economist Edward L. Glaeser and two doctoral students, Jesse M. Shapiro and Giacomo A. M. Ponzetto. (The paper, “Strategic Extremism: Why Republicans and Democrats Divide on Religious Values,” is online.)
I was expecting an analysis of voting and going to church as economic substitutes. That’s not what I got though:
The paper starts with a puzzle: In a majoritarian system like ours, political economists generally predict that candidates will converge toward the center of the spectrum, so as to attract as many votes as possible. This is the “median voter theory.” But it doesn’t seem to describe what’s happened in American politics. On divisive religious issues like abortion, the two parties aren’t hugging the center. They’re abandoning it.
What explains this?
First, there are actually two important voting decisions — not just whom to pick but whether to vote at all. Candidates need to get their voters excited enough to come to the polls (or possibly to give money). Extreme positions can do that.But positions that energize your base may also encourage the opposition to come out against you. That’s where the second part of the model comes in. Candidates need a way to target their messages so their supporters are more likely to respond than their opponents.
That’s where social groups like churches and unions come in. These groups provide friendly forums for candidates’ direct or indirect messages. While outsiders may know something about a candidate’s more extreme positions, group members know more — because the messages are aimed specifically at them.
[...]
Those in-group forums work, however, only if the groups are just the right size. They have to be small enough to be homogeneous and big enough to be influential. “The model has this very odd prediction that the power of social groups is most when they’re roughly 50 percent of the population,” Professor Glaeser said.If a group is too small, it’s not worth courting. But if it’s too big, it includes too many of your opponent’s supporters, making targeted messages impossible. If everybody goes to church or belongs to a union, membership in either group will not predict voting behavior.
In areas (and times) where almost everyone goes to church (the Philippines, South Carolina, Minnesota in the 1970s), church attendance doesn’t predict voting preference.