The TRUE MathAssume that current state polls reflect the will of the electorate and a fraud-free election is held today. The

**2008 Election Model** indicates that given the following undecided voter allocations (UVA), Obama’s projected 2-party vote share and expected (mean) electoral vote are:

**UVA**

50%

60%

75%

80%

**Vote**

51.3%

52.0%

53.0%

53.3%

**Evote**

325

340

359

364

**EV Wins** (in a Monte Carlo simulation of 5000 election trials)

4966

4996 (base case scenario)

5000

5000

Note: the polls were taken prior to the debate — so Obama’s numbers should improve as a result.

Obama is projected to win

**53.9%** of the two-party vote based on the most recent 5 national polls. The national tracking polls include one-day of sampling post-debate. Since the national polls lead the states, we can expect a rise in Obama’s expected EV. With a 53.3% state poll aggregate, he could expect 364 EV (see the table).

View the

**State vs. National vote share projection Trend**.

But what if the election is not fraud-free? Assuming

**3%** of votes cast are

**uncounted** (75% of which are traditionally Democratic) and

**4%** of Obama’s votes are

**switched** electronically to McCain, Obama would lose by

**277**–

**261** EV with

**49.4%** of the two-party vote (see the election fraud sensitivity table below).

This was the

**electoral vote.com map on Nov 1, 2004**.

The expected electoral vote is calculated by the formula:

EV = Σ P(i) * EV(i), where i = 1,51

P(i) is the probability of winning state (i) with EV(i) electoral votes.

The probability P(i) of winning state (i) is based on the projected state vote share V(i).

The projected vote share is equal to the latest poll plus the undecided voter allocation.

V(i) = Poll(i)+UVA(i)

The state win probability is calculated using the Excel Normal distribution function, assuming a 4.0% MoE for a typical 600-sample poll:

P(i) = NORMDIST ( V(i), 0.5, .04/1.96, true )

The electoral votes, current poll numbers, projected vote shares and win probabilities for all the states are given in the table below.

Electoral-vote.com and

RealClearPolitics have Obama leading by

**286**–

**252**. They assign the state electoral vote to the poll leader, regardless of the spread. This is mathematically incorrect, since win probabilities are dependent on the spread — which they do not use in calculating the EV. Furthermore, undecided voters are NOT allocated.

On the other hand,

FiveThirtyEight has Obama leading by

**318**–

**220**. But the win probability of

**79%** is much too low — it should be close to 98%. This indicates a problem with the simulation algorithm and/or the state win probabilities. The

electoral vote distribution chart is not a continuous normal distribution bell-curve; there are discrete jumps in the bin totals. The curve should be smooth and symmetric around the mean (expected EV) which is within 1 EV of the median in a 5000 Election trial Monte Carlo simulation. The Election Model

Electoral Vote Simulation Frequency chart is a continuous, bell-shaped EV frequency histogram.