Worried that the Bradley Effect may be skewing polling results? Jon Perr on The Daily Kos covers the topic thoroughly:
If this formula sounds vaguely familiar, it should. That’s because back in the early 1990s political scientists, pundits, and the press proclaimed the existence of the “Bradley Effect” in which some white voters would lie to survey takers (and even themselves) about supporting a black candidate only to mark the ballot for his or her white opponent on Election Day. The Trump campaign, it now appears, is counting on the reverse dynamic to save it in November. …
In September 2008, the legendary Sam Wang of the Princeton Election Consortium weighed in on “The Disappearing Bradley Effect.” As more analysts suggested the polls would contain a hidden bonus for John McCain, Wang cautioned the usual conventional wisdom peddled by the likes of Ron Fournier:
Now comes a large-scale empirical study (in preprint form) by Harvard political scientist Dan Hopkins. He finds that since the mid-1990s, the Bradley effect has disappeared. His paper is a must-read…Until now, the empirical evidence for the Bradley effect rested on individual cases…Now Dan Hopkins has gathered some highly relevant information. In a recent paper he analyzes polling data and election outcomes for 133 gubernatorial and Senate races from 1989 to 2006…
Polls did show a significant Bradley/Wilder effect through the early 1990s, which includes the period when Bradley and Wilder were running for office. However, Hopkins notes that the effect then went away in races from 1996 onward. To quote the study: “Before 1996, the median gap for black candidates was 3.1 percentage points, while for subsequent years it was -0.3 percentage points.”
And there’s lots more.
