Which Pre-Election Poll was Most Accurate?
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).
3. PPP (D)
3. Daily Kos/SEIU/PPP
6. Pew Research*
6. Hartford Courant/UConn*
7. Purple Strategies
11. Democracy Corps (D)*
12. FOX News
12. Washington Times/JZ Analytics
12. Newsmax/JZ Analytics
12. American Research Group
12. Gravis Marketing
13. National Journal*
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.
Founded in 1841, Fordham is the Jesuit University of New York, offering exceptional education distinguished by the Jesuit tradition to more than 15,100 students in its four undergraduate colleges and its six graduate and professional schools. It has residential campuses in the Bronx and Manhattan, a campus in West Harrison, N.Y., the Louis Calder Center Biological Field Station in Armonk, N.Y., and the London Centre at Heythrop College in the United Kingdom.