Public service announcement: 'unadjusted' exit polls and the hucksters who tout them are misleading
also posted in Gee-dee-pee, where the latest conspiracy theory has also been posted
1. Anytime you see someone citing "unadjusted exit polls" they are a quack, a fraud, and a charlatan.
An essential part of exit poll methodology is to weight them by turnout. If they sample voters at two precincts, they can't properly weight the exit poll results from those precincts until they know how many people voted at those precincts, relative to the entire state. Unadjusted exit polls give only very, very rough estimates, and are completely worthless for picking a winner in a reasonably close race, such as Michigan or Massachusetts this year.
http://www.mysterypollster.com/main/2004/11/exit_polls_what.html
2) The mid-day numbers do not reflect weighting by actual turnout – the end-of-day exit poll used to assist the networks in determining winners will be weighted by the actual turnout of voters at each selected precinct. The weighting will then be continuously updated to reflect turnout at comparable precincts. In the past, mid-day numbers have reflected a weighting based on past turnout, so the leaked mid-day numbers may tell us nothing about the impact of new registrants or the unique level of turnout this time.
One point needs emphasis here: even in past elections, networks never called an election based on raw exit poll numbers alone. They were first weighted by a tally of the full day's turnout at each sampled precinct. This end-of-day data is (obviously) not available at 12 noon.
2. Exit polls often get it wrong
http://www.nytimes.com/2014/11/05/upshot/exit-polls-why-they-so-often-mislead.html?_r=0
The imperfections of the exit polls are not hard to show. Here are two quick examples, based on official voter turnout statistics:
The exit polls showed that voters over age 65 were 18 percent of the electorate in Iowa in 2008, but 26 percent in 2012. The official state turnout statistics instead show that the share increased to 23.6 percent, from 21.9 percent, over the same span.
In North Carolina, the exit polls showed that the black share of the electorate dropped to 23 percent in 2008, from 26 percent in 2004, and held steady at 23 percent in 2012. The state turnout statistics say the share rose from 18.6 percent in 2004 to 22.3 percent in 2008, and then to 23.1 percent in 2012.
Please, don't believe bullshit some crank tells you on the Internet because it's what you want to believe.
