Should the Democrats move to the left on economic policy?

The 2008 primary election season is just beginning, and, amid the debates between Hillary Clinton, Barack Obama, John Edwards and others, there’s been active discussion about whether the country is looking for a centrist “New Democrat” in the Bill Clinton mode or someone from Howard Dean’s “Democratic wing of the Democratic party.”

One way to get a handle on this question is to consider the strategies considered in 2004. Could John Kerry have gained votes in the recent Presidential election by more clearly distinguishing himself from George Bush on economic policy? At first thought, the logic of political preferences would suggest not: the Republicans are to the right of most Americans on economic policy, and so it would seem that the optimal strategy for the Democrats would be to stand infinitesimally to the left of the Republicans. The “median voter theorem” (as political science jargon puts it) suggests that each party should keep its policy positions just barely distinguishable from the opposition.

In a multidimensional setting, however, or when voters vary in their perceptions of the parties’ positions, a party can benefit from putting some daylight between itself and the other party on an issue where it has a public-opinion advantage (such as economic policy for the Democrats). Is this reasoning applicable in 2004 (or today)?

What we did

Our paper has two parts. In the theoretical part, we set up a plausible model in which the Democrats could achieve a net gain in votes by moving to the left on economic policy, given the parties’ positions on a range of issue dimensions. In the data-analysis part, we fit a set of regression models based on survey data on voters’ perceptions of their own positions and those of the candidates in 2004.

For example, here is a graph based on National Election Study data from 2004. Each dot represents where a survey respondent places him or herself on economic and social issues: positive numbers are conservative and negative numbers are liberal, and “B” and “K” represent the voters’ average placements of Bush and Kerry on these scales:


Most voters tend to place themselves to the right of the Democrats on economic and on social issues, and most voters tend to place themselves to the left of the Republicans in both dimensions. Having (approximately) located the voters, we fit a model estimating the probability that each person would vote for Bush or Kerry, given the person’s distance from each of the two candidates on economic and social issues. We can then artificially imagine moving the candidates to the left or right and seeing what would happen to their votes.

What we found

Under our estimated model, it turns out to be optimal for the Democrats to move slightly to the right but staying clearly to the left of the Republicans’ current position on economic issues.

First, here are the estimated results based on one-dimensional shifts; that is, Kerry or Bush shifting to the left or the right on economic or social issues. Positions on the economy and on social issues are measured on a -9 to 9 scale, and a -8 to 8 scale, respectively, so shifts of up to 3 points to the left or right are pretty large (see the scatterplot above to get a sense of where the voters stand, and how they rate the candidates). For all shifts, the graphs show the estimated change in Bush’s share of the vote.


Based on this model, Kerry should’ve shifted slightly to the right in both dimensions, Bush should’ve shifted slightly to the left on social issues and a great deal to the left on economic issues. (The curves are slightly jittery because of simulation variability.)

Now here are the estimated results for two-dimensional shifts, in which a candidate can change his position on economic and social issues:


According to this model, the optimal strategy for Kerry is to move 1 point to the right in both dimensions; in contrast, Bush would benefit by moving about 2 points to the left on social issues and nearly 3 points to the left on the economy. (Recall that the scales go from -9 to +9.)

In summary . . .

The answer to the question posed by the title of the paper appears to be No, Kerry should not have moved to the left on economic policy. Conventional wisdom appears to be correct: Kerry would have benefited by moving to the right, and Bush by moving to the left. The optimal shifts for Bush are greater than those for Kerry, which is consistent with the observation that voters are, on average, closer to the Democrats on issue attitudes.

Does this make sense?

Could the Democrats really move a bit to the left or the right? I think they could; there’s been various debate along these lines in the 2008 primary season, with Hillary Clinton generally viewed as the more centrist candidate and John Edwards being more to the left on economic issues.

Could the Republicans move strongly toward the center, as recommended by our calculations? This seems less likely, given that the debates among the Republicans in the primaries seem to be focusing more on establishing the candidates’ conservative credentials.

We conclude with a reminder that candidates need not, and perhaps should not, necessarily follow these seemingly optimal strategies. For one thing, the recommendations are only as good as the models, and the very act of a candidate trying to move to the left or to the right could affect voters’s attitudes and other ways. For another thing, you only need 50%-plus-one electoral votes to win the election, and sometimes that can be done with a position that is less than optimal, as with George Bush’s successful 2004 campaign, where he did fine without having to move to the center. He might have won more states with more centrist positions, but he didn’t need to.


This is based on the article, “Should the Democrats move to the left on economic policy?” by Andrew Gelman and Cexun Jeffrey Cai, to appear next year in the Annals of Applied Statistics.

9 thoughts on “Should the Democrats move to the left on economic policy?

  1. I disagree, but the reason for my disagreement is outside the scope of your analysis: it is that while the Republicans have moved right over the past thirty years, and the Democrats have moved right as well, the median voter is still not to the left of the Democrats. How is that possible?

    I think what happened instead is that the median voter followed the median politician. Ironically, for all that people criticise politicians for being followers of polls and not leaders of them, they actually have been leaders, or at least the Republicans have been.

    The question is, what is politics for? Is it to gain office and a lucrative Washington career, followed by a comfortable retirement, or is it to change the country, because you don't like the way it is now? The Republicans have been very successful at the latter, again ironically, as they're the ones usually called the mercenaries while the Democrats are called the idealists. On the other hand, Republican idealism has not been without personal profit for them either. The "Overton Window" (which see) is a path both to national change *and* a comfortable retirement.

    I'm sure your statistical conclusion is quite valid, that if Median Voter Theory is correct, the Democrats should drift right. It's just that I don't think Median Voter Theory is correct.

  2. Derek, I would have to agree with you.

    I wonder, too, if maybe the left-right continuum isn't an especially accurate model for political opinion. It may be good at describing how people perceive themselves. But that's as much a function of people believing that the left-right spectrum is accurate. Most people, of course, place themselves somewhere in the middle of the spectrum. But is that really an accurate description of their position? Most people have been told that it's best to find a moderate position in general to seem reasonable.

    Granted, campaigns use people's perceptions of themselves to craft their messages to get elected. And this, essentially, I think is what this paper is considering.

    A similar example (I just throw this out, please poke holes in this if they're obvious to you) would be people's understanding of evolution. I would guess that as people understand that humans didn't actually descend from apes (which they didn't) and realize that apes and humans have common ancestors their acceptance of evolution is more likely.

    I've always disliked the left-right spectrum model of political opinion. I consider it a decent shorthand, but I suspect there's a better model.

    Just a late-night ramble…

    Eric Aspengren


  3. Ah, I just read the paper and it's much more clear now.


    PS. I think I used my nickname (phat) in my previous post. Old habit, I'm afraid.

  4. It might be worth looking at the formal model on the origins of "flanking moves", outlined by Gary Miller and Norman Schofield in "Activists and Partisan Realignment in the United States" APSR 2003. (doi:10.1017.S0003055403000650)

  5. "Kerry should have moved to the right"

    Huh. I look at those graphs and see something else entirely. It looks to me like Kerry's positions were essentially optimal — he could have reduced Bush's vote share by what, .2% if he picked issue positions that were ex ante perfect? (I'm eyeballing it here). Even in a close election that's nothing, unless all .2% were in a single swing state. The way I read your graph, it looks like "Kerry could have done a whole lot worse in the issue space and essentially no better at all". Kerry's (0,0) is on an isoquant labeled "0" in your graph!

    Even a slight policy preference would pull him this far left of the minima, considering that to the first order it isn't losing him any votes. Or any history of positions that would make it costly for him to tack to the right (either in his legislative record or his primary campaign). Or any other factor that makes it slightly costly for a politician to pick any position on an issue.

    And, might I add, this difference of .2% or whatever has gotta be well within the error introduced by the inevitable simplification and abstraction inherent in a model like this. Bush's economic policy on the other hand….

  6. I skimmed the paper, looking for what questions you used to define "left" and "right" as regards economics, but I didn't find them. What caused me to wonder is your use, in the introductory paragraph, of Howard Dean as an example of the economic "left". How do you figure?

    Dean was perceived as liberal in the primary overwhelmingly due to his opposition to the war in Iraq. On economic matters, I can think of only one question — willingness to raise taxes — on which he can be considered to the left, and that position came out of his steadfast adherence to the principle of keeping a balanced budget, generally considered a position of the right. On pretty much every other issue, too — tariffs, deregulation, market-based incentives, etc — I would characterize Howard Dean as fiscally conservative relative to the rest of the field in the 2004 Democratic primary.

    Maybe it's because I'm not a statistician, but it's hard for me to take any interest in your conclusions when I can't even tell what you mean by "left" and "right". Is your data flawed, or just your introductory paragraph? If by "left" you mean what I assume you mean, then surely you could have found a better example. Edwards, perhaps.

  7. Ubs,

    Howard Dean's "Democratic wing" is, I think, associated with more liberal economic policies, even if Howard Dean himself does not have these views. I guess the thing to do is to check the 2004 primary election poll data and see if Dean's supporters were more economically liberal than supporters of other Democratic candidates.

    We do say in the paper how "left" and "right" are defined–it's in a footnote, I think. It was tough because there were only a few issues where the survey asked about the respondents' own views and about their perceptions of where Bush and Kerry stand.

  8. Fascinating paper.

    Seems like it would be relatively straightforward to add a 'propensity to vote' factor, where the likelihood of voting is higher if a candidate is very close to one's own views…..

Comments are closed.