How to Predict the Winner of the Presidential Election

Bell CurveHow to Predict the Winner of the Presidential Election

(This formula and method predicted the last US Congressional election to the seat!)

Spoiler: Romney 56 – 44%

Here’s the ‘How To…’, it is straightforward and intuitive –

We’re going to use something called the normal distribution, aka the Bell Curve and The Law of Large Numbers, to help w/ the forecast. You can learn more about the normal distribution here: http://en.wikipedia.org/wiki/Normal_distribution.

The key idea to predicting the election outcome is understanding the ‘tails’ – the extremes on the left and right of the curve. We’re going to let these tails represent the people who will always vote republican or democrat without regard to who is running and we’re going to say about 20% of the entire voting population lies in each tail. That leaves 60% of the population in the middle. Remember each election cycle when you hear ‘it’s the middle that matters’? This is why. They are the undecided voters – the ‘tails’, made up their minds long ago.

So how do we divide up the 60% that makes up the middle? The country is a bit more conservative than it is liberal, http://www.gallup.com/poll/148745/political-ideology-stable-conservatives-leading.aspx, so we’ll say 60% of the middle will vote for Romney and 40% will vote for Obama – the same split that was used to exactly predict the outcome of the last congressional elections. (You can, and probably should, apply your own splits here. Play w/ the numbers a bit, make them your own).

Given ‘a bit more conservative than liberal’ we have:

Obama: 20% (the left tail) + (40% * the middle 60%) = 20% + 24% = 44%

Romney: 20% (the right tail) + (60% * the middle 60%) = 20% + 36% = 56%

Romney wins, 56 – 44%.

For fun and practice, let’s add in Ron Paul as a third party candidate and estimate he pulls in half the Republican tail and 25% of he middle which we’ll take from Obama and Romney (so the middle is now split 28% Obama, 48% Romney and 24% Paul by taking 12% away from each candidate based on the idea that Paul’s ‘freedom’ appeals equally across the middle):

Obama: 20% (the left tail) + (28% *  the middle 60%) = 20% + 17% = 37%

Romney: 10% (50% of the right tail) + (48% * the middle 60%) = 10% + 29% = 39%

Paul: 10% (50% of the right tail) + (24% * the middle 60%) = 10% + 14% = 24%

Romney wins, 39%-37%-24%. Note the importance of the middle.

Good questions to ask now are:

Can Obama, whose Senate and Presidential careers are both liberal relative to the country, win back the middle and change the 60-40% distribution?

What happens if Romney chooses Paul as his running mate and takes another 12% of the middle from O’bama?  (ans: Romney wins, 63 – 37%)

Forecast (all scenarios): Romney win.

 

–h

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