The Case Against Polls

I wrote today's Idea of the Day over at the Atlantic's special ideas report. The idea is to "Get Rid of Polls," although that might be putting it a bit strongly. The more temperate version would be "the case against polls." In particular, I think polls have impose three costs on American democracy. (I'll put them after the jump.) I'm not sure how large these costs are. But I'm also not sure what to put on the other side of the ledger: What are the public benefits of polling? I can see why a public official might want to read them. But does the public gain anything?

Anyway, here are the three costs:

First, constant polling uncomfortably expands the domain of democracy. There are, of course, lots of ways in which the U.S. might be able to use a little more democracy. (Think the Senate.) But the value of the referendum has its limits. (Think California.) Writers have been whining about the "tyranny of the majority" since Tocqueville for a reason: getting the input of the citizenry at regularly appointed intervals has real benefits--among them stability and reliability and the chance for a politician or policy to succeed or fail within reasonable time constraints. Poll-testing every decision, on the other hand, disturbs the balance between democratic legitimacy and democratic effectiveness.

Second, many polls are wrong. Which isn't to say that the opinions the American people express in polls are factually incorrect, though that's sometimes true. What I mean is that polls are a terrible indicator of the citizenry's actual preferences. Part of the problem is that people have a tendency to say one thing ("stated preference") and then do another ("revealed preference"). Another part of the problem is that the public is sometimes simply confused.

My favorite recent example of such confusion pertains to cap and trade. According to one poll, three-quarters of Americans think the U.S. should regulate greenhouse-gas emissions, with a slight majority saying they would support a cap-and-trade program of the type now being considered in the Senate. But as another poll makes clear, most Americans don't even know what cap and trade is: slightly fewer than one-quarter of respondents could even identify it as having something to do with the environment.

Third, and of perhaps greatest concern: the outcome of one poll can affect future polls and behavior. As behavioral scientists and economists are fond of pointing out--in books like Nudge and Predictably Irrational--popular behavior can snowball. Public-health campaigns emphasizing how few teenagers smoke are more effective in deterring teen smoking than those that emphasize lung cancer or bad breath. Likewise, the perception that a candidate or political position is popular today will make the candidate or position more popular in the future. As Cass Sunstein and Richard Thaler put it in Nudge, "Nothing is worse than a perception that voters are leaving a candidate in droves." Voters should be free to switch allegiances whenever they want, but they should do so for substantive reasons, not because they're following the flock.