Here’s a picture from my paper with Jonathan and Gary a few years ago that appeared in the volume Rethinking the Vote, but it’s actually a graph that Gary and I made around 1994 or so. The graph shows the share of the two-party popular vote that the Democrats needed to have a 5%, 50%, or 95% chance of winning the electoral college in each year:

In most years, things were pretty balanced (each party has some close states and some not-so-close states, each party wins some big states and some small states). We haven’t done 2008 but I suspect it would be similar. That’s the conclusion of this paper by Phillip Ardoin and Bryan Parsons:

Our [Ardoin and Parsons's] research provides a direct analysis of the multiple sources of bias within the electoral college and examines their individual impact on each party’s electoral fortunes over the last eleven elections (1964-2004) with particular attention on the 2000 and 2004 presidential elections. Our results are in line with previous analyses indicating no significant bias within the electoral college.

Bryan Caplan, author of The Myth of the Rational Voter (formerly called The Logic of Collective Belief: The Political Economy of Voter Irrationality), wrote some nice things about our book and also posted a variant of this graph that I made by putting together a bunch of exit polls:

Bryan also comments that, to his eyes, the correlation between income and voting is pretty small. He writes, “As an economist, I [Caplan] was raised to expect virtually all poor people to be Democrats, and virtually all rich people to be Republicans. From this starting point, Gelman’s data show that income is practically irrelevant.” I agree that income matters less than one might think in the U.S., and it actually matters even less in most other countries for which we have data. As we discuss in the book, the correlation between income and economic ideology is low (and it varies quite a bit by state). On the other hand, it’s a difference of 20% between the high and low end, and that ain’t nothing. It’s the difference between voting like Massachusetts and voting like Texas. We’re always dancing around the magic 50% point, and so even small differences can be important. As Bryan says, a lot of how you interpret this depends on where you’re coming from.

I also agree with Bryan that we are not really shooting down the ideas of journalists and others, but rather looking at polls and elections in a different way. We did try to convey in the book that we respect the insights of the many journalists who’ve talked about the red-blue divide, and that we’re trying to go further by seeing how these divisions have changed over time and how they vary across different groups of the population.

From our forthcoming Red State, Blue State book, here are some data going back to 1968 (from the National Election Study) on the voting patterns of different religious groups:

Perhaps also of interest is how this relates to religious attendance. More frequent attenders are more likely to vote Republican, but the pattern varies by denomination. Here’s what was happening in 2004 (as estimated from the Annenberg pre-election survey):

The graph for 2000 looks similar except that the line for Jews was flat in that year (maybe just a small-sample thing, I don’t know that I’d take it too seriously).

A reporter asked me, “Do people run for VP, who in the past, how, has it worked or failed?”

My reply: I haven’t looked at this recently, but I recall when studying election forecasting 15 years ago, that the estimated effect of VP choice was something like +3 percentage points in the VP’s home state, so nothing huge.

What about national effects? In 1988, I recall that polls found that Bush alone (in a Bush vs. Dukakis matchup) did about 2 points better than Bush-Quayle vs. Dukakis-Bentsen. But this is probably an upper bound:
- Quayle was a horrible candidate
- And probably, when it came down to the voting booth, it’s my guess that less than 2% of people decided not to vote for Bush on the basis of Quayle.
See also Nate Silver’s thoughts on the topic.

So probably the biggest effect of VP is that this is a person who’s likely to become president. (I don’t have the stats on this, but the total probability must be pretty high.) If I were choosing, I’d pick the person I’d most like as a future president and probably not worry so much about electoral calculations, fun though they are to think about.

Just in case you come to this site and don’t realize . . . it’s all about our new book, Rich State, Poor State, Red State, Blue State: Why Americans Vote the Way They Do. Just click on any of the tabs at the top of this page for more information.

To follow up on the previous entry on McCain and Obama’s chances, here’s Bob Erikson and Chris Wlezien’s 2008 forecast based on economic conditions and the polls. They write:

On the eve of the election, the presidential vote can be seen fairly clearly from trial-heat polls. Earlier in the election year, the polls off much less information about what will happen on Election Day. The polls capture preferences to the moment and do not—because they cannot—anticipate how preferences will evolve in the future, as the campaign unfolds. Various things ultimately impact on the final vote. The standing of the sitting president is important. The economy is too. Both can change as the election cycle evolves. To make matters worse, late-arriving economic shocks have a bigger impact on the electoral verdict than those that arrive earlier. This complicates forecasting the vote well in advance. Our [Erikson and Wlezien's] solution to the problem of early forecasting has been to turn to the index of leading economic indicators. In previous papers we have shown that the growth in these indicators through the Spring of the election year—quarter 13 of the election cycle—is a strong predictor of the vote.

They fit the model to past election sand go on to plug in some numbers to get a point prediction with uncertainty.

The paper will appear in the journal PS (in the same special issue that will contain my article with Kastellec and Chandler).

The economy is going badly, Bush is unpopular, so why is Obama up only slightly in the polls? This is the question that is (currently) puzzling the political world. A quick answer: the economy isn’t going so badly by historical standards, and Bush’s popularity isn’t so relevant given that he’s not running for reelection. Forecasting models based on past elections predict Obama to get something like 53% of the two-party vote–but these forecasts aren’t perfect; they have a margin of error of a few percentage points. (This is not the margin of error of the polls, arising from sampling variation; rather, it’s the uncertainty reflected by the imperfections of the forecasting model as applied retrospectively to past elections.) In short: macro conditions for the Republicans are not so bad as all that: Obama is a legitimate favorite but there’s no reason to expect that there would be a landslide. Things are going about how one might suspect based on historical patterns of the economy, incumbency, and presidential elections.

To think about it another way, consider this graph adapted from Doug Hibbs of incumbent party’s vote share and economic growth, for all presidential elections since 1952.

As you can see, the incumbent party sometimes loses but they never have gotten really slaughtered. In periods of low economic growth, the incumbent party can lose, but a 53-47 margin would be typical; you wouldn’t expect the challenger to get much more than that. Such things can happen (see, for example, Eisenhower’s performance against Stevenson in 1952) but it wouldn’t be expected.