Stephen Jessee sent me this paper (joint work with Doug Rivers) on party identification and voting. He writes,

I [Jessee] show that most people do in fact have some level of policy ideology that has an important effect on their voting behavior. The influence of party identification, however, is also quite strong. Judging from the baseline of Downsian policy voting, I show that independents, even those with lower levels of political sophistication, perform quite well on average, and engage in essentially unbiased spatial policy voting. Partisans of similar levels of sophistication, by contrast, are systematically pushed away from more rational decision rules and seem to be making biased choices in translating their policy preferences into vote choices. On the whole, it seems clear that party identification operates more as a systematic bias than a profitable heuristic.

Continuing, Jessee writes,

One school sees party identification as informing and shaping people’s views of the political elements they encounter—a lens through which citizens see the political world. The other side, by contrast, sees party identification as a product of citizens’ experiences with the two parties. . . . Bartels (2002) refutes the claim that people incorporate new information into their political beliefs in a rational, mostly unbiased manner. He argues that Republicans and Democrats differ in the way in which they update their beliefs based on new information. In addition to this, Bartels demonstrates that this phenomenon cannot be solely the result of differing preferences, since respondents’ statements about objective facts, such as whether unemployment increased or decreased during the Reagan administration, are also heavily colored by party identification.

OK, now my thoughts:

1. The basic message reminds me of Joe Bafumi’s paper on “the stubborn American voter.” Joe’s paper also has the time dimension–stubbornness has increased since the 1970s–and I’d like to see that in the Jessee model also.

2. The particular point–that Dem identifiers vote more for the Dem, and Rep identifiers vote more for the Rep, even after accounting for ideological distances from the candidates–is something that Jeff Cai and I noticed here (see the intercepts in the estimated models on page 10 of our paper). However, we didn’t really take much notice of it this pattern, since we’d expect to see this pattern. Jessee goes a bit further than we do in considering a more elaborate model as well as using vote choices for senators as well as president.

3. The idea of putting together an individual-voting model and an ideal-point model looks cool. I haven’t looked at the details carefully, but I’m surprised there’s no distance model (for example, (ideal point of voter – ideal point of candidate 1)^2 – (ideal point of voter – ideal point of candidate 2)^2).

4. I don’t really like the description on pages 27-28 of Bayesian inference in terms of prior and posterior beliefs. I know that a lot of people think of it this way, but I’d rather think of Bayesian inference as a way of fitting a model to data and working out its implications (see our Bayesian book, especially chapters 1 and 2 (for more on where prior distributions come from) and chapter 6 (for more on the use of Bayesian methods to check model fit).

5. I like all the graphs! Regarding the tables: Table 1 should lose the horizontal lines, also I’d order the bills from the most liberal to the most conservative ideal point (as indicated by the roll call votes). Table 2 should be a graph, of course, or else just a simple display of fitted equations. All those significant figures aren’t needed.

6. Is Josh Clinton really a Jesuit priest or is that S.J. just a peculiarity in how the referencew were done?

The big issue

Returning to point 2 above, the big thing that Jessee is emphasizing is that party ID is predictive of vote, even after conditioning on issue positioning. This is something that’s so familiar that I’ve never before thought of it as something worth commenting on. Democrats (mostly) vote for Democrats, Republicans mostly vote for Republicans–that’s what it’s all about. Jessee is putting a twist on this by calling party voting biased, with his key assumption being that if voting were unbiased, then people would vote only on the issues, and party ID would add no predictive power.

I’m not quite sure what to think about this. It’s an audacious claim–taking a familiar observation about party ID and turning it into a stylized fact that needs explaining. I have a couple of problems with the reasoning, though. First, I could imagine that it would be rational to vote for my party’s presidential candidate, even if I were otherwise indifferent on the issues, for other reasons, including nominations to the Supreme Court and other appointive positions, the desire to put a check on the other party’s power in Congress, and anticipated future policy questions. Thinking more generally, if I take representative government seriously, I might vote for the representative I like/trust (from the party I trust) rather than voting on specific issues or ideological positions, which might not be relevant for the future.

Beyond this, I’m not so comfortable with calling these differences “biases” or even “heuristics.” Party ID just seems so fundamental, in so many ways. But maybe I’m just thinking in an old-fashioned way; I’m willing to be convinced by Jessee, Rivers, and others on this.