Measuring 'the Decoy Effect' in Political Races The presence of a third candidate in political races often has the unintended effect of benefiting one or the other of the two front runners. Shankar Vedantam of the Washington Post talks about the psychological phenomenon known as "the decoy effect."
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Measuring 'the Decoy Effect' in Political Races

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Measuring 'the Decoy Effect' in Political Races

Measuring 'the Decoy Effect' in Political Races

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It's still nine months before any voters actually get to have a say on who'll be next year's presidential candidates. But, as we all know, the race for the nomination is already well underway. The latest horserace polls show a lot of flux on the Republican side.

The Los Angeles Times-Bloomberg poll has Senator John McCain, who used to be called the obvious frontrunner, in third place now, behind former New York Mayor Rudolph Giuliani, former senator and current actor Fred Thompson, who hasn't even entered the race. Former Massachusetts Governor Mitt Romney is behind them, but doing well at fundraising.

The Democratic field seems to be a little clearer. Clinton, Obama and then, John Edwards, followed by several other candidates. That same poll shows Senator Hillary Clinton in first place, about 10 points ahead of Senator Obama. But John Edwards' third place showing is strong. And psychologists say that who's in third place can have a strong effect on how somebody may choose number one.

Shankar Vedantam wrote about what psychologists called this decoy effect in his Washington Post column. He joins us now. Mr. Vedantam, thanks so much for being with us.

Mr. SHANKAR VEDANTAM (Columnist, Washington Post): Thanks so much for having me, Scott.

SIMON: Before we get into politics, let's talk about how the decoy effect works in other, maybe, more mundane areas of life. You heard about, for example, a study by a marketing professor at Duke University who took a look at restaurant choices.

Mr. VEDANTAM: That's right. Joel Huber, who's a marketing professor at Duke University, gave this example. I'm going to change his numbers a little bit just to make it easier for your listeners. Imagine you're choosing between two restaurants, one of them is a five-star restaurant that's five miles away, and the other is a three-star restaurant that's three miles away.

Now if the better restaurant was also closer, there would be no dilemma at all. But as in many choices we have to make in life, we have to trade off, in this case, quality against convenience. Now what Huber did is he introduced a third option to a group of people. He said, what if you had a four-star restaurant that was six miles away?

And when he presented that option, a lot of people said, well, the five-star restaurant that's five miles away is both better than and closer than the new third candidate, so it's probably the best restaurant of all.

But when Huber presented a different group of people with a different third option, a two-star restaurant that was four miles away, now the three-star restaurant started looking a lot better on both quality and convenience, whereas the five-star restaurant was better than this new option only on quality.

What's interesting about it is that the third candidate, in this case, the third restaurant, is always inferior to either one of the front-running candidates. And so in a rational world, you should assume that it would have no effect whatsoever on our decision, but it has a pretty big effect on which restaurant we end up choosing.

SIMON: Let's chance nosing into politics with this. How could this ostensibly play out on either party?

Mr. VEDANTAM: Well, politics is a little bit more complicated for several reasons. For one thing, you have often many more than just two or three candidates. Also, people are thinking not just of one or two dimensions such as quality and convenience, but they're thinking of dozens of different issues. You know, your position on the war in Iraq, your position on health care. Your position on taxes, and they're playing off all of these issues against one another in their heads. So it's a very complicated decision.

But what the decoy effect suggests is that when you have two frontrunners, and as you pointed out, the Democratic field right now does have two frontrunners -Barack Obama and Hillary Clinton. The characteristics that people perceive John Edwards bringing to the race can subtly alter whether they think Obama or Clinton is the better candidate.

SIMON: How could the qualities that Senator Edwards projects, in theory, affect how people wind up feeling about Senator Obama and Senator Clinton?

Mr. VEDANTAM: Before I give the example, I should also mention that the decoy effect works only if you're an undecided voter. Let's say an undecided centrist, Democratic voter, and you like Clinton on the fact that she's strong on national security. But you also want somebody who's a fresh face in Washington, and you like Obama on that issue.

So now let's say you have Edwards enter the race. And you see Edwards as more dovish than Obama on national security issues, but also part of the same establishment as Clinton. He was, after all, the vice-presidential candidate in the last election.

So Obama now looks better than Edwards on both counts, whereas Clinton beats Edwards on only the national security issue. And if you configure Edwards differently in the mind of this undecided voter, Clinton could end up looking much better than Obama, which is why it could potentially stand to the advantage of both Clinton and Obama to draw attention to certain characteristics of Edwards but not to others.

But politics is a volatile game and, you know, you talk up a third candidate too much, and the third candidate could stop being a third candidate and become a frontrunner.

SIMON: And what about on the Republican side, any guesses?

Mr. VEDANTAM: The Republican side is a little bit more confusing, I think, because it's changing so rapidly. So, I think, it's safe to say the decoy effect is probably playing a role, but how exactly, you know, I would be hesitant to make an assertion about that.

SIMON: Do you think the decoy effect had any discernible outcome in the election of 2000?

Mr. VEDANTAM: Well, you know, before I reported this column I would have said the presence of Nader in the race, you know, tipped the election to Bush, especially in Florida because some or many of those 9,000 votes of Nader would have gone to Gore if Nader had not been in the race.

After reporting this column, I'm actually not entirely sure that that's true. I think it's possible that Nader did indeed take away some votes from Gore, people essentially who were to the left of Gore, who found Nader to be a more appealing candidate.

But I think it's also possible that Nader ended up pulling some voters, who were undecided between Gore and Bush to the Gore camp. And the way I would think about this is, imagine a straight line where you have Gore on the left and Bush on the right. And let's say you have an undecided voter who is somewhere in the middle between Gore and Bush, and now you have Nader enter the race and Nader is to the left of Gore. And what essentially the presence of Nader does is it tips the overall scale, so that Gore feels like the better candidate among the three candidates that this voter is thinking about.

And so it's possible that the presence of Nader in the race actually drew many voters to the Gore camp. Whether Nader ended up taking more votes away from Gore than he ended up giving to Gore, that I don't think anyone really can answer.

SIMON: Mr. Vedantam, thanks so much.

Mr. VEDANTAM: Thank you for having me, Scott.

SIMON: Shankar Vedantam writes the Department of Human Behavior column for The Washington Post.

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