2.7.08 Those Darn Polls

Mark Twain often cited three types of lies: “lies, damned lies, and statistics.” After another series of presidential polling blunders, we wonder if Twain would have added opinion polls as a fourth lie.

To be fair, opinion polls serve a vital role in any democracy. Government of the people relies on knowing what the people are thinking, and opinion polls allow any politician to get a vivid glimpse into American opinion on any issue at any particular point in time.

When it comes to presidential politics, the internet now provides a bewildering number of opinion polls that try to predict electoral outcomes. While many can be amazingly accurate, some have proven to be incredibly off.

The most notable of the inaccurate polls predicted Barack Obama as the big winner of the New Hampshire and California primaries. But the cause of the polling errors might have more to do with the big changes we have seen in these elections rather than big changes in public opinion.

To accurately predict whom voters will support on Election Day, a pollster must first determine who will be a voter. Surveys of “likely voters” typically define likely in many different ways. Besides asking if a respondent will vote on Election Day, they might also ask a series of filters: Have you voted in the last two elections? Have you ever voted in a primary? Have you ever not voted?

So when voter turnout is very high, as it has been this primary season, the poll might prove to be inaccurate because so many unlikely voters actually turn out.

The biggest change that has affected the accuracy of opinion polls seems to be the new phenomenon of early voting.

Nearly 1 million Californians used early voting before this week’s Super Tuesday election. Polls that took a snapshot of popular opinion in the days before the election might not have been able to gauge those opinions that had been cast as votes weeks ago.

This is yet another reminder that, while polls are crucial in feeling the pulse of American opinion, the Election Day ballot box still remains the most important and most accurate electoral survey.