How the Final 2004 and 2008 National Exit Polls were forced to match the recorded vote

How the Final 2004 and 2008 National Exit Polls were forced to match the recorded vote

Richard Charnin

Jan. 6, 2011

This is a quick summary of the changes that were made to the unadjusted, pristine exit polls in order to force them to match the recorded vote.

1988-2008 Unadjusted State and National exit polls vs. recorded votes and National True Vote Model

https://docs.google.com/spreadsheet/pub?key=0AjAk1JUWDMyRdFIzSTJtMTJZekNBWUdtbWp3bHlpWGc&output=html

2000
Adjusted Final NEP ‘Voted 1996’ – forced to match the recorded vote. Gore 48.4-47.9%
Unadjusted National Exit Poll (13,108 respondents): Gore  48.5-46.4%.
Unadjusted state exit poll aggregate (57,866 respondents): Gore 50.8-44.4%.
True Vote Model:  Gore 51.6-44.7%.

2004
Adjusted Final NEP ‘Voted 2000’ – forced to match the recorded vote. Kerry 48.3%
Unadjusted National Exit Poll (13660 respondents). Kerry had 51.7%.
Adjusted Final NEP ‘Gender’ – forced to match the recorded vote Kerry had 47.8%.
Unadjusted NEP ‘Voted 2000’ (3182 respondents). Kerry had 51.7%.
Unadjusted state exit poll aggregate (76192 respondents). Kerry had 51.1%.
True Vote Model. Kerry had 53.6%.

Based on the 3182 respondents who were asked how they voted in 2000:
1- The unadjusted 2004 NEP implies that Gore had 47.8%, Bush 48.4%, Other 3.8%.
2- The Final 2004 NEP implies that Gore had 44.6%, Bush 51.8%, Other 3.6%.
But Gore won the popular vote by 540,000 and had 50.8% in the unadjusted exit poll.
The unadjusted 2004 exit poll understated Kerry’s True Vote share by nearly 2%.

2008
Adjusted Final NEP ‘Gender’ – forced to match the recorded vote. Obama had 52.7%.
Adjusted Final NEP ‘Voted 2004’ – forced to match the recorded vote. Obama had 52.9%.
Unadjusted NEP total (17836 respondents). Obama had 61.0%.
Unadjusted NEP ‘Voted 2004’ (4178 respondents). Obama had 58.0%.
Unadjusted state exit poll aggregate (82388 respondents). Obama had 58.1%.
True Vote Model. Obama had 58.0%.

Based on the 4178 respondents who were asked how they voted in 2004:
1- The unadjusted 2008 NEP implies that Kerry had 50.2%, Bush 44.6%, Other 5.2%.
This is close to the unadjusted 2004 NEP (Kerry 51.7%), but the 3rd party (Other) recorded share was 1.0%, a 4.2% discrepancy from the implied share.

2- The Final 2008 adjusted NEP implies that Kerry had 42.3%, Bush 52.6%, Other 4.6%.
This is far from the unadjusted and Final 2004 NEP (Kerry 48.3%).
The discrepancy is due to the Final 2008 NEP being forced match to the recorded vote.

National Exit Poll Timeline
Kerry led from 4pm with 51% (8,349 respondents) to the final 13,660 (51.7%). The exit pollsters had to switch 471 (6.7%) of Kerry’s 7,064 responders to Bush in order to force the Final NEP to match to the recorded vote.
Given his 51.7% share of 125.7 million votes cast, Kerry won by nearly 6 million votes. But the True Vote Model indicates he had 53.6% and won by 10 million.

11/3/04 1:24pm, Final National Exit Poll, 13660 respondents
http://www.richardcharnin.com/US2004G_3970_PRES04_NONE_H_Data.pdf

Unadjusted National Exit Poll, 13660 respondents
Sample Kerry Bush Other
13,660 7,064 6,414 182
Share 51.7% 47.0% 1.3%
http://webapps.ropercenter.uconn.edu/CFIDE/cf/action/catalog/abstract.cfm?label=&keyword=USMI2004-NATELEC&fromDate=&toDate=&organization=Any&type=&keywordOptions=1&start=1&id=&exclude=&excludeOptions=1&topic=Any&sortBy=DESC&archno=USMI2004-NATELEC&abstract=abstract&x=32&y=9

11/2/04 12:22am, 13047 respondents
Kerry 51%; Bush 48%
http://media.washingtonpost.com/wp-srv/politics/elections/2004/graphics/exitpolls_us_110204.gif

11/2/04 7:33pm, 11027 respondents
Kerry 51%; Bush 48%
http://www.richardcharnin.com/US2004G_3798_PRES04_NONE_H_Data.pdf

11/2/04 3:59pm, 8349 respondents
Kerry 51%; Bush 48%
http://www.richardcharnin.com/US2004G_3737_PRES04_NONE_H_Data-1.pdf

2004
Final Exit Polls
http://www.cnn.com/ELECTION/2004/pages/results/states/US/P/00/epolls.0.html

2008
Final Exit Polls
http://www.cnn.com/ELECTION/2008/results/polls/#val=USP00p1

Election Model Forecast; Post-election True Vote Model

2004 (2-party vote shares)
Model: Kerry 51.8%, 337 EV (snapshot)
State exit poll aggregate: 51.7%, 337 EV
Recorded Vote: 48.3%, 255 EV
True Vote Model: 53.6%, 364 EV

2008
Model: Obama 53.1%, 365.3 EV (simulation mean)
Recorded: 52.9%, 365 EV
State exit poll aggregate: 58.0%, 420 EV
True Vote Model: 58.0%, 420 EV

2012 (2-party state exit poll aggregate shares)
Model: Obama 51.6%, 332 EV (Snapshot)
Recorded: 51.6%, 332 EV
True Vote Model: 55.2%, 380 EV