Monday, January 18, 2010

Are the MASS polls right? Will Demo Coakley lose?

Charles Franklin at provides a good analysis of the confusing recent Massachusetts Senate polls. He points out that “no matter how you slice the data, the only reasonable conclusion is that Republican Scott Brown has moved from well behind Democrat Martha Coakley to a lead of somewhere between 4 and 11 points.” average has Brown up 6 points (51.1% to 44.8% for Coakley). That’s very discouraging news for Democrats.

However, Franklin points out that we have seen quite a bit of variation between polls in this race. Normally, 95% of polls fall within +/- 5 points of linear trend estimates. However, in Massachusetts with this special election ONLY HALF of the current polls are within +/- 5 points of the linear trend. That could mean that the polls could be very, very wrong.

Franklin notes that in the New York 23rd Congressional District special election last November the last three polls had the Republican candidate, Hoffman up by 5, 5 and 17 points over the Democrate Bill Owens.’s final trend estimate based on all the polls had Hoffman up by 5, 41.8 to 36.8. The final election results showed that Owens prevailed by a margin of 48.3% to 46%

Polling in a special election is quite different and more difficult than polling in general elections. We can only hope that tomorrow we will see a repeat of the Hoffman/Owens election.

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