Bradley effect

The Bradley effect (less commonly the Wilder effect) is a theory concerning observed discrepancies between voter opinion polls and election outcomes in some United States government elections where a white candidate and a non-white candidate run against each other. The theory proposes that some voters who intend to vote for the white candidate would nonetheless tell pollsters that they are undecided or likely to vote for the non-white candidate. It was named after Los Angeles Mayor Tom Bradley, an African-American who lost the 1982 California governor's race despite being ahead in voter polls going into the elections.

The Bradley effect posits that the inaccurate polls were skewed by the phenomenon of social desirability bias. Specifically, some white voters give inaccurate polling responses for fear that, by stating their true preference, they will open themselves to criticism of racial motivation. Members of the public may feel under pressure to provide an answer that is deemed to be more publicly acceptable, or 'politically correct'. The reluctance to give accurate polling answers has sometimes extended to post-election exit polls as well. The race of the pollster conducting the interview may factor into voters' answers.

Some analysts have dismissed the theory of the Bradley effect, or argued that it may have existed in past elections, but not in more recent ones, such as when Barack Obama was elected and re-elected President of the United States in 2008 and 2012 respectively. Others believe that it is a persistent phenomenon. Similar effects have been posited in other contexts, for example, the Shy Tory Factor and spiral of silence.

In 1982, Tom Bradley, the long-time mayor of Los Angeles, ran as the Democratic Party's candidate for Governor of California against Republican candidate George Deukmejian, who is white (of Armenian descent). Most polls in the final days before the election showed Bradley with a significant lead. Based on exit polls, a number of media outlets projected Bradley as the winner and early editions of the next day's San Francisco Chronicle featured a headline proclaiming "Bradley Win Projected." However, despite winning a majority of the votes cast on election day, Bradley narrowly lost the overall race once absentee ballots were included. Post-election research indicated that a smaller percentage of white voters actually voted for Bradley than polls had predicted, and that previously undecided voters had voted for Deukmejian in statistically anomalous numbers.

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