It Wasn’t “Polling Error.” You didn’t read the fine print

Polling error is almost never reported in headlines. The plus or minus percentage without which the polling data is useless. But that is all about statistics, and as we know, math is hard. Why FiveThirtyEight Gave Trump A Better Chance Than Almost Anyone Else | FiveThirtyEight

The referenced article is a review of polling statistics by one of the polling organizations. They gave Trump a 30 percent chance of winning on Tuesday, so they aren’t claiming to be clairvoyant, but they do explain why the polls (and the papers) got it so wrong.

First off, the polls didn’t get it that wrong.

In fact, the error in national polls wasn’t any worse than usual. Clinton was ahead by 3 to 4 percentage points in the final national polls. She already leads in the popular vote, and that lead will expand as mail ballots are counted from California and Washington, probably until she leads in the popular vote by 1 to 2 percentage points overall. That will mean only about a 2-point miss for the national polls. They may easily wind up being more accurate than in 2012, when they missed by 2.7 percentage points.

But, as the article points out, the election is not determined nationally, but at the state level. And there are a lot of problems at the state level when it comes to polling.

But the real issue is one of perception and bias.

It’s one thing to criticize pollsters — or polling-based forecasts — if your personal prediction came closer to getting the outcome right. But I’d assert that most mainstream journalists would have given Trump much lower odds than the 30 percent chance that FiveThirtyEight gave him, and that most campaign coverage was premised on the idea that Clinton was all but certain to become the next president. Both reporters and pundits criticized FiveThirtyEight and other polling sites for not accounting for early voting data, for example, on the idea that it portended good news for Clinton that our model ignored. As we’ve discovered in the past, however, it’s hard to make inferences from early voting and attempts to do have a fairly bad track record — as they did this year.3

The Left Coast and the New York/Washington corridor pundits just don’t understand the middle of the country. And they have no desire to correct that. They are busy calling us names (as they have done for years) and not bothering to wonder at the 53% of white women who rejected Hilary, or the 29% of Hispanics that voted for Trump. They don’t want to upset their tiny minds with anything that is not an approved idea.

And so they were worried that Trump supporters would not accept the outcome of the election, and instead we have rioting in the streets of our liberal-enclave cities.

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