National House Ballot Update, November 12th

by: Chris Bowers

Thu Nov 12, 2009 at 15:00

Last update: Nov 11: Democrats +4.47

Polls included in the calculation

Poll Sponsor	Poll Mid-Date	Democrats	Republicans
Total	Nov 12	42.50	38.33
Gallup	Nov 07	44	48
Rasmussen	Nov 05	37	43
Daily Kos	Nov 04	35	30
Pew	Nov 03	47	42
Economist	Nov 02	46	37
AP	Oct 31	48	41
CNN	Oct 31	50	44
Rasmussen	Oct 29	38	42
Daily Kos	Oct 28	36	28
Economist	Oct 26	47	41
NBC / WSJ	Oct 24	46	38
Rasmussen	Oct 22	38	42
Daily Kos	Oct 21	37	28
Economist	Oct 19	45	36
PPP	Oct 18	48	40
ABC / WaPo	Oct 17	51	39
Rasmussen	Oct 15	37	42
Daily Kos	Oct 14	35	29

1. Until the final six weeks of the election, take the simple mean of virtually all polls where the majority of interviews were conducted over the last 30 days.

2. During the final six weeks of an election, use the simple mean from the last 15 days.

3. Do not include Zogby Interactive polls and Columbus Dispatch polls, due to their horrendous past performance and questionable methodologies.

4. Do not include Strategic Vision polls, as it is starting to seem likely those are not real polls.

5. Include campaign-funded polls. Further, if there is more than one poll from a single organization, include all of them.

This is different from my 2006 and 2008 methodology in that it includes polls from 15 days out from an election, instead of only 8. Further, campaign funded polls, and multiple polls from a single polling firm, are now included. All of these changes were made to include more polls in the averages, since my previous methodology was about 10-20% less accurate than Pollster.com and fivethrityeight.com. Since they had already raised the bar so high, and since they will probably improve their methodologies for 2010 even more, it was time for Open Left to step it up.