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TruthIsAll
12-21-2008, 08:21 PM
2008 Election Calculator: A Comprehensive Sensitivity Analysis

TruthIsAll

Dec. 25, 2008

http://www.geocities.com/electionmodel/2008ElectionSensitivityAnalysis.htm


Election models consist of recorded data, assumptions (parameters), and calculations. Given that the mathematical logic in the 2008 Election Calculator (EC) is correct, the assumptions should be realistic in order to determine the True Vote. The EC base case assumptions are the best estimates derived from the following data sources: 2008 National Exit Poll and 2004 unadjusted aggregate state exit polls, 2004 and 2008 official recorded vote, voter mortality tables, historical returning voter turnout percentages, Census total votes cast. Due to the margin of error in the data and assumptions, a thorough examination of the effects of changes in the assumptions on the vote share is necessary in order to have confidence in the model.

The EC contains a comprehensive set of sensitivity analysis tables. Each table is a 5x5 matrix of a two-variable range of assumptions. The combinations display the effects on vote share and margin. It is very likely that the True Vote is located in one of the 25 matrix cells; the best estimate is that it is in the central cell. The range of plausible True vote shares is reduced from 25 to 9 by focusing on the combinations that lie within the margin of error.

The Final 2008 National Exit Poll vote shares of returning 2004 and new voters are used as the base case. Since these shares were used to match the recorded vote, it makes perfect sense to use them for the base case. The model calculates the returning voter mix based on plausible, documented assumptions for 2004 uncounted votes, voter mortality and 2004 voter turnout in 2008. Along with the NEP vote shares, the assumptions comprise the base case in the sensitivity analysis.

Two general cases will be analyzed. The first assumes that the 2004 election was legitimate and uses the recorded vote shares; the second assumes fraud: Kerry won by the unadjusted exit poll shares.

To analyze the effect of incremental changes in the data assumptions, compare the most-likely base case vote share and margin (central cell) to the worst case (lower left cell) and best case (top right cell).

These are the base case assumption estimates:
1) The US Census determined that 2.74% (3.45m) of 125.74m votes cast in 2004 were uncounted.
2) 3.0% of votes cast in 2008 will be uncounted.
3) Obama and Kerry each won approximately 75% of the uncounted vote (over 50% of uncounted votes are in minority districts).
4) 1.2% annual voter mortality (18+ years old).
5) 95% of Kerry, Bush and Other voters still living in 2008 turned out to vote.
6) 2008 Final NEP vote shares. Approximately 4000 respondents (2% MoE for vote shares depending on the margin).

For those who believe the 2004 election was legitimate:
Scenario 1: The returning 2004 voter mix is based on the Recorded Vote (Bush 50.73-Kerry 48.27%)

For those who believe the 2004 election was stolen:
Scenario 2: The returning 2004 voter mix is based on the Unadjusted Exit Poll (Kerry 52.0-Bush 47.0%)

The tables display the Obama vote share and margin over a range of:
Table 1- Obama share of New and Kerry voters
Table 2- Obama share of New and Bush voters
Table 3- Uncounted vote rates and Obama share of Kerry voters
Table 4- Uncounted vote rates and Obama share of Bush voters
Table 5- Voter mortality rates and Obama share of Kerry voters
Table 6- Voter mortality rates and Obama share of Bush voters
Table 7- Kerry vote shares and Obama share of Kerry voters
Table 8- Kerry vote shares and Obama share of Bush voters
Table 9- Voter mortality rates and Kerry Turnout
Table 10- Voter mortality rates and Bush Turnout
Table 11- Obama share of Kerry and Bush voters
Table 12- Kerry share of uncounted vote and Obama share of Bush voters

Scenario 1: 2004 recorded vote (Bush 50.7- Kerry 48.3%)
Obama base case margin: 17.7m (55.6%)

Scenario 2: unadjusted 2004 exit poll (Kerry 52.0-Bush 47.0%)
Obama base case margin: 22.6m (57.5%)

Effect of a 1% change in Election Calculator model assumptions on the Obama vote margin (in millions):
Variable: change in margin
Obama share of Kerry voters: 1.2
Obama share of Bush voters: 1.1
Obama share of new voters: 0.9
Kerry voter turnout: 0.2
Voter mortality (4-year): 0.2
Kerry vote share: 1.5
Effect of a 5% change in the Kerry share of uncounted votes: 0.2

Examples of the effect of other changes in assumptions (Scenario 2):
The base case Obama True Vote share is 57.5% (22.6m vote margin).

The base case 2004 voter turnout in 2008 is 95% for all candidates.
What if 91% of Kerry voters and 95% of Bush voters returned to vote?
The effect on vote share is minimal: 57.2% (21.7m vote margin).

The base case annual voter mortality is 1.2% (4.8% over 4 years).
What if 2000 voter mortality was 0.8% (3.2% over 4 years)?
The effect on vote share is minimal: 57.3% (22.0m vote margin).

The base case Obama share of Kerry voters is 89% (National Exit Poll).
What if the share was 87%?
The effect on vote share and margin is significant: 56.6% (a 2.4m decrease in margin to 20.2m).
For the 4195 exit poll sample and 89% share, the margin of error is 1.14% (20% cluster effect).
The probability of a 2% deviation is 1 in 3500.

http://www.geocities.com/electionmodel/ElectionCalculator_454_image001.gif

http://www.geocities.com/electionmodel/ElectionCalculator_15960_image001.gif





2008 Election Calculator
TruthIsAll
Dec. 23, 2008


2004 Unadjusted State Exit Poll Aggregate (WPE/IMS) 2008 Calculated
Exit Poll Unctd Cast Deaths Alive Turnout Voted Mix Obama McCain Other
DNV 21.71 16.0% 71% 27% 2%
Kerry 63.59 1.79 65.38 3.14 62.25 95% 59.13 43.7% 89% 9% 2%
Bush 57.47 1.62 59.09 2.84 56.26 95% 53.44 39.5% 17% 82% 1%
Other 1.23 0.03 1.26 0.06 1.20 95% 1.14 0.84% 66% 24% 10%

Total 122.30 3.45 125.74 6.04 119.70 113.7 135.43 100% 57.51% 40.82% 1.67%
Cast 135.43 77.88 55.28 2.27
Recorded 52.87% 45.62% 1.51%
131.37 69.46 59.94 1.98



Sensitivity Analysis: Obama Vote share and Margin
Scenario: 2004 Unadjusted State Exit Poll Aggregate (WPE/IMS)

Table 1 Table 2
Share
of New Share of Kerry Share of Bush
85% 87% 89% 91% 93% 13% 15% 17% 19% 21%

75% 56.4% 57.3% 58.1% 59.0% 59.9% 56.6% 57.4% 58.1% 58.9% 59.7%
73% 56.1% 57.0% 57.8% 58.7% 59.6% 56.3% 57.0% 57.8% 58.6% 59.4%
71% 55.8% 56.6% 57.5% 58.4% 59.3% 55.9% 56.7% 57.5% 58.3% 59.1%
69% 55.4% 56.3% 57.2% 58.1% 58.9% 55.6% 56.4% 57.2% 58.0% 58.8%
67% 55.1% 56.0% 56.9% 57.7% 58.6% 55.3% 56.1% 56.9% 57.7% 58.4%

Margin
75% 19.6 22.0 24.3 26.7 29.1 20.1 22.2 24.3 26.5 28.6
73% 18.7 21.1 23.5 25.8 28.2 19.2 21.3 23.5 25.6 27.7
71% 17.9 20.2 22.6 25.0 27.3 18.3 20.5 22.6 24.7 26.9
69% 17.0 19.4 21.7 24.1 26.5 17.5 19.6 21.7 23.9 26.0
67% 16.1 18.5 20.9 23.2 25.6 16.6 18.7 20.9 23.0 25.1


Table 3 Table 4
Unctd
Rate Share of Kerry Share of Bush
85% 87% 89% 91% 93% 13% 15% 17% 19% 21%

4% 55.9% 56.8% 57.6% 58.5% 59.4% 56.1% 56.9% 57.6% 58.4% 59.2%
3% 55.8% 56.6% 57.5% 58.4% 59.3% 55.9% 56.7% 57.5% 58.3% 59.1%
2% 55.6% 56.5% 57.4% 58.3% 59.1% 55.8% 56.6% 57.4% 58.2% 59.0%
1% 55.4% 56.3% 57.2% 58.1% 59.0% 55.6% 56.4% 57.2% 58.0% 58.8%
0% 55.3% 56.2% 57.1% 58.0% 58.9% 55.5% 56.3% 57.1% 57.9% 58.7%

Margin
4% 18.5 20.9 23.2 25.6 28.0 18.9 21.1 23.2 25.4 27.5
3% 17.9 20.2 22.6 25.0 27.3 18.3 20.5 22.6 24.7 26.9
2% 17.3 19.6 22.0 24.4 26.7 17.7 19.9 22.0 24.1 26.3
1% 16.7 19.0 21.4 23.8 26.1 17.1 19.3 21.4 23.5 25.7
0% 16.1 18.4 20.8 23.2 25.5 16.5 18.7 20.8 23.0 25.1

Table 5 Table 6
Mortality
Rate Share of Kerry Share of Bush
85% 87% 89% 91% 93% 13% 15% 17% 19% 21%

1.6% 56.0% 56.9% 57.7% 58.6% 59.5% 56.2% 57.0% 57.7% 58.5% 59.3%
1.4% 55.9% 56.8% 57.6% 58.5% 59.4% 56.1% 56.8% 57.6% 58.4% 59.2%
1.2% 55.8% 56.6% 57.5% 58.4% 59.3% 55.9% 56.7% 57.5% 58.3% 59.1%
1.0% 55.6% 56.5% 57.4% 58.3% 59.2% 55.8% 56.6% 57.4% 58.2% 59.0%
0.8% 55.5% 56.4% 57.3% 58.2% 59.1% 55.7% 56.5% 57.3% 58.1% 58.9%

Margin
1.6% 18.6 20.9 23.2 25.5 27.9 19.0 21.1 23.2 25.3 27.4
1.4% 18.2 20.6 22.9 25.3 27.6 18.7 20.8 22.9 25.0 27.2
1.2% 17.9 20.2 22.6 25.0 27.3 18.3 20.5 22.6 24.7 26.9
1.0% 17.5 19.9 22.3 24.7 27.1 18.0 20.1 22.3 24.4 26.6
0.8% 17.2 19.6 22.0 24.4 26.8 17.6 19.8 22.0 24.2 26.3

Table 7 Table 8
Kerry
Vote Share of Kerry Share of Bush
85% 87% 89% 91% 93% 13% 15% 17% 19% 21%

53% 56.3% 57.2% 58.1% 59.0% 59.9% 56.6% 57.3% 58.1% 58.9% 59.7%
52% 55.8% 56.6% 57.5% 58.4% 59.3% 55.9% 56.7% 57.5% 58.3% 59.1%
51% 55.2% 56.0% 56.9% 57.8% 58.6% 55.3% 56.1% 56.9% 57.7% 58.5%
50% 54.6% 55.5% 56.3% 57.1% 58.0% 54.7% 55.5% 56.3% 57.1% 57.9%
49% 54.0% 54.9% 55.7% 56.5% 57.3% 54.0% 54.9% 55.7% 56.5% 57.4%

Margin
53% 19.4 21.8 24.3 26.7 29.1 20.1 22.2 24.3 26.3 28.4
52% 17.9 20.2 22.6 25.0 27.3 18.3 20.5 22.6 24.7 26.9
51% 16.3 18.6 21.0 23.3 25.6 16.6 18.8 21.0 23.1 25.3
50% 14.8 17.0 19.3 21.6 23.9 14.8 17.1 19.3 21.5 23.8
49% 13.2 15.4 17.7 19.9 22.1 13.1 15.4 17.7 19.9 22.2

Table 9 Table 10
Mortality
Rate Kerry Turnout Bush:95% Bush Turnout Kerry:95%
91% 93% 95% 97% 99% 91% 93% 95% 97% 99%

1.6% 57.4% 57.6% 57.7% 57.9% 58.1% 58.6% 58.2% 57.7% 57.3% 56.9%
1.4% 57.3% 57.5% 57.6% 57.8% 57.9% 58.5% 58.1% 57.6% 57.2% 56.7%
1.2% 57.2% 57.3% 57.5% 57.7% 57.8% 58.4% 58.0% 57.5% 57.1% 56.6%
1.0% 57.1% 57.2% 57.4% 57.6% 57.7% 58.3% 57.8% 57.4% 56.9% 56.5%
0.8% 56.9% 57.1% 57.3% 57.4% 57.6% 58.2% 57.7% 57.3% 56.8% 56.4%


Margin
1.6% 22.3 22.8 23.2 23.7 24.1 25.6 24.4 23.2 22.0 20.8
1.4% 22.0 22.5 22.9 23.4 23.8 25.3 24.1 22.9 21.7 20.5
1.2% 21.7 22.2 22.6 23.0 23.5 25.1 23.8 22.6 21.4 20.1
1.0% 21.4 21.8 22.3 22.7 23.2 24.8 23.5 22.3 21.1 19.8
0.8% 21.1 21.5 22.0 22.4 22.9 24.5 23.2 22.0 20.7 19.5

Table 11 Table 12
Share
of Bush Share of Kerry Kerry Share of Uncounted
85% 87% 89% 91% 93% 52% 70% 75% 80% 90%

21% 57.3% 58.2% 59.1% 60.0% 60.8% 59.1% 59.1% 59.1% 59.1% 59.1%
19% 56.6% 57.4% 58.3% 59.2% 60.0% 58.3% 58.3% 58.3% 58.3% 58.3%
17% 55.8% 56.6% 57.5% 58.4% 59.3% 57.5% 57.5% 57.5% 57.5% 57.5%
15% 55.0% 55.8% 56.7% 57.6% 58.5% 56.7% 56.7% 56.7% 56.7% 56.7%
13% 54.2% 55.1% 55.9% 56.8% 57.7% 55.9% 55.9% 55.9% 55.9% 55.9%

Margin
21% 22.1 24.5 26.9 29.2 31.6 26.9 26.9 26.9 26.9 26.9
19% 20.0 22.4 24.7 27.1 29.5 24.7 24.7 24.7 24.7 24.7
17% 17.9 20.2 22.6 25.0 27.3 22.6 22.6 22.6 22.6 22.6
15% 15.7 18.1 20.5 22.8 25.2 20.5 20.5 20.5 20.5 20.5
13% 13.6 16.0 18.3 20.7 23.1 18.3 18.3 18.3 18.3 18.3