Which public poll came closest to the actual 2012 presidential election results?

Costas Panagopoulos, Ph.D., director of Fordham’s Center for Electoral Politics and Democracy and associate professor of political science, has ranked which polling organizations were the most accurate of the 28 organizations he analyzed, based on their pre-election polling.

“For all the ridicule directed towards pre-election polling, the final poll estimates were not far off from the actual nationwide vote shares for the two candidates,” said Panagopoulos.

For all the derision directed toward pre-election polling, the final poll estimates were not far off from the actual nationwide voteshares for the two candidates. On average, pre-election polls from 28 public polling organizations projected a Democratic advantage of 1.07 percentage points on Election Day, which is only about 1.13 percentage points away from the current estimate of a 2.2-point Obama margin in the national popular vote (Obama 50.3% versus Romney 48.1%).

Following the procedures proposed by Martin, Traugott and Kennedy (see Public Opinion Quarterly, Fall 2006, pp. 342-369) to assess predictive accuracy, Panagopoulos analyzes poll estimates from 28 polling organizations. Most (22) polls overestimated Romney support, while six (6) overestimated Obama strength (indicated with a * below), but none of the 28 national preelection polls he examined had a significant partisan bias.

The following list ranks the 28 organizations by the predictive accuracy of their final, national pre-election estimates (as reported on pollster.com).

1. Democracy Corps (D)*
2. Pew Research
2. Hartford Courant/UConn
4. Angus-Reid
5. National Journal*
6. Ipsos/Reuters
7. YouGov
8. PPP (D)
8. Daily Kos/SEIU/PPP
9. Purple Strategies
10. YouGov/Economist
13. Monmouth/SurveyUSA
13. Politico/GWU/Battleground
13. FOX News
13. Washington Times/JZ Analytics
13. Newsmax/JZ Analytics
13. American Research Group
13. Gravis Marketing
14. Rasmussen
14. Gallup
15. NPR
16. AP/GfK

In 2008, Panagopoulos released the first such report following the 2008 presidential election. The good news is that for the past two presidential elections, pre-election polling has been fairly accurate.

– Costas Panagopoulos