A recent post on Nate Silver’s critically acclaimed FiveThirtyEight blog offered a detailed look at how skewed internal polling was in the 2012 election cycle, particularly the Romney Campaign’s polling.
For those that need a refresher, “internal polls” refer to the made for press release surveys taken by campaign consultants, the results of which are always massaged in favor of the candidate. Internal polls are often lauded more for their fundraising ability (look, the race is close!) and PR value, rather than their accuracy, and as Silver reports, they were six percentage points more favorable to the candidate than independent polls. That’s quite the spin:
“My database of campaign polls released to the public in United States House races found that they were about six points more favorable to their candidate than independent surveys on average — and that they were typically less accurate in the end.
The traditional explanation for this phenomenon is that the subset of campaign polls that are released to the public is subject to a type of selection bias. Campaigns conduct polls all the time, but only occasionally disclose these results to the public and will be much more inclined to do so when the numbers are favorable for their candidates (especially in comparison to independent polls). In essence, the internal polls that filter their way into the public domain may be the outliers…
The release of internal campaign polls is not that different from any other form of spin in this respect — but that is precisely the point. Internal numbers that a campaign releases to the public should be thought of less as scientific surveys and more as talking points.”
Additionally, Silver reminds us that since pollsters are people too, they’re more likely to overrate their own candidate’s chances:
A pollster working within a campaign may face a variety of perverse incentives that compete with his ability to produce the most accurate possible results to his candidate. He may worry about harming the morale of the candidate or the campaign if he delivers bad news. Or he may be worried that the campaign will no longer be interested in his services if the candidate feels the race is hopeless.