The Election Model (EM) assumes as a base case that a fraud-free election is held today — and that current polls reflect the true vote. The
state model projects Obama will win the True Vote by
76–
62m. For McCain to win, he needs approximately
10% of Obama’s votes
switched to his column (see the table below).
Obama exceeded 350 EV in 4862 of 5000 Monte Carlo election trial simuations, so there is a
97.2% probability that he will win at least
350 EV. He has a
58% probability of exceeding
380 EV (he won 2902 trials with more than 380 EV).
The
BAD news: The Gallup
LV poll has Obama’s lead down to 2 points,
49–
47%; the
RV poll has him ahead by
50–
43%. The AP poll (
43–
42) generated lots of angst and had very implausible internals.
The
GOOD news: the Pew
RV poll has Obama up by a whopping 16 points (
52–
36%) — and that’s BEFORE undecided voters are allocated. Pew is a well-known polling firm with a long history. One week ago, the Pew
LV poll also indicated a commanding Obama
53–
39% lead. The polls portend a
MAJOR True Vote landslide. Regarding the AP poll, the two-party share was just 85%. If we
allocate 2/3 of the “other” 15% to Obama, we get a 6% spread (
53–
47%).
The
undecided vote allocation is based the assumption that Obama is the
challenger and McCain is running for Bush’s third term (GWB is
not the most popular of incumbents). In fact, the Election Model (EM)
base case allocates a conservative 60% of the undecided vote to Obama; most pollsters would typically assign 70–90%, depending on the incumbent’s approval rating.
The
most critical states weighted by the electoral vote and poll spread (see below) are now
FL, IN, NC, OH, MO, AZ and GA. The latest polls indicate that these states are a virtual lock:
PA, MI, WI, MN, IA. With one week to go, the latest polls indicate that Obama is even within striking distance of winning these red states: Arizona (10 EV), Georgia (15), Montana (3) and North Dakota (3).
National polls are current; state polls lag the nationals by a week on average. But over the past few days, Obama’s projected state aggregate 2-party vote (
55.2%) has exceeded the national average (
53.5%). At the same time, Obama’s
expected EV keeps rising. View the
Electoral vote and projected vote share trend. Battleground state polls are now more frequent then they were a month ago, therefore the state poll aggregate should more closely match the national. View the
State vs. National vote share projection Trend.
The EM calculates an average of the two or three most recent state polls. It projects five vote share scenarios (5000 election trials each) over a range of undecided voter allocations (UVA) from
40–90%. Obama won the base case scenario (60%) with an average
379.3 EV. The median and mode were both 381. Even in the worst-case scenario (40%), he won all 5000 trials.
The Monte Carlo mean EV (
379.31) matches the theoretical summation formula EV (379.49) based on state win probabilities. This illustrates The Law of Large Numbers (LLN): 5000 simulated election trials were required for the MEAN EV to CONVERGE to the THEORETICAL EV (the simulation is in the “long run”). It is computational overkill to perform a
meta analysis requiring the calculation of millions of EV combination scenarios in order to calculate the win probabilities.
Polling data source:
Electoral-vote.comRealClearPolitics.comFull Update with State Model: Obama Projected Vote vs
Kerry Projected Vote http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=132&topic_id=7647439&mesg_id=7647439