Princeton Election Consortium

A first draft of electoral history. Since 2004

Meta-Margins for control: House D+2.8% Senate R+5.6% Find key elections near you!

Calculation Change; Getting Out the Vote

October 19th, 2004, 12:00pm by Sam Wang


Today I implement the first major change to this calculation – I am allocating undecided voters. To do this I use past presidential election voting patterns, specifically the incumbent rule as described by Charlie Cook of the National Journal. This gives a more accurate snapshot and is a step toward making an actual prediction.

Rationale: It is known to poll analysts that voters who are undecided usually end up voting against the incumbent. In particular, compared with their final poll numbers, incumbents get between 2% less and 1% more. In contrast, challengers do better on average by 3%. These figures are consistent with Cook’s estimate that undecideds split at least 75% for the challenger. In today’s summary of national polls, the average Bush-Kerry split is 48.5-45.5, which sums to 94%. Assuming 2% for Nader and other candidates, the remaining undecideds are 4%. Splitting these by Cook’s rule gives 1% to Bush and 3% to Kerry, reducing the margin by 2%.

Therefore, for the main calculation I will assume that the undecided-voter shift is +2.0% towards Kerry, shift state polls by this amount (using the variable already provided in the script), and proceed with the calculation. Based on state polls in Florida, Ohio and Pennsylvania, I estimate that the proportion of undecided voters in these states is similar to the national figures. Because national polls come more frequently, I will use them to calculate the shift. The size of this shift may change in the final days, and I will be monitoring this.

This new estimate is likely to be more accurate. However, it is also the first change to the calculation that is not neutral: it goes beyond the polling numbers themselves, and it is in a direction that is favorable to my candidate. For example, Florida, Iowa, Ohio and Wisconsin are still toss-ups, but they are now above the 50% probability threshold for Kerry. Therefore I will continue to report the results without this adjustment. This is listed in the box above on the line labeled “Decided voters only.” The corresponding Meta-Margin can be calculated by subtracting 2.0% from the value listed.

To read more about the incumbent rule, see Charlie Cook, Guy Molyneux, the Los Angeles Times, Mark Shields, the Mystery Pollster, and a contrarian.

I have also simplified the box by removing the line about the Colorado ballot initiative, which, based on a recent poll and Salazar’s opposition, seems likely to fail.

Finally, I will continue listing rankings and probabilities for all states. I have decided that there is little benefit to leaving these out.

Hitting the streets: How much do you affect the election by getting out the vote? Also, where are your efforts most valuable? To help guide your efforts, here is a synthesis of previous posts. Once you decide, I recommend contacting your local Democratic (or Republican) organization or America Coming Together.

This question can be answered by calculating how much the Electoral College win probability is changed by one person’s vote. This affects where you should go because as an individual, you can only get out a finite number of votes. Today the best states to go to are Iowa, Ohio, Nevada, and Florida. Nevada, while small, is on the list because it is a near-tossup and relatively few voters per electoral vote. Here is a case study. If you are a New Jersey resident, your vote has some value, but it is low since the state is very likely to go Democratic by a substantial margin. In contrast, driving a voter to the polls in Pennsylvania is worth nearly 300 times as much. If you go to Ohio each vote is worth even more, over 500 “jerseyvotes.” The top states are IA (686 jerseyvotes), OH (528), NV (508), FL (372), NM (304), WI (295), PA (295), MO (199), AR (151).

Although the calculation is unbiased, I am not. I am a Democrat. To see a list of races I consider critical, see my ActBlue page. My advice to all voters (including Republicans) is the same: Go to battleground states. Register voters. Make phone calls and knock on doors (a very effective strategy) to canvass for voters. Vote absentee or vote early (online resource), and on Election Day, work to get out the vote.

Tags: 2004 Election

No Comments so far ↓

Like gas stations in rural Texas after 10 pm, comments are closed.