Question

Metaculus Help: Spread the word

If you like Metaculus, tell your friends! Share this question via Facebook, Twitter, or Reddit.

FiveThirtyEight 2020 Popular Vote Accuracy

FiveThirtyEight is a website that was founded as a poll aggregator and now covers news on a variety of topics with a focus on statistics, polling, economics, and related subjects. It has had notable forecast successes in the past and had among the highest likelihoods for Donald Trump among several forecasters in the 2016 election. It continues to provide polling averages as well as a 2020 election forecast.

Trump's election in 2016 was a surprise to most forecasters, in part due to polling error that showed Hillary Clinton as having a larger level of support than actually materialized in the election. One hypothesized contributor to polling error in the 2020 election is the "shy Trump voter" effect, in which Trump voters do not tell others how they intend to vote for fear of political backlash. The existence of this effect is still under debate; FiveThirtyEight's team discussed this possibility on its Politics podcast and generally considered it unlikely.

How will Trump's popular vote share compare to FiveThirtyEight's prediction?

Trump's predicted vote share (among Biden and Trump votes) will be computed by dividing his popular vote share in FiveThirtyEight's forecast by the total of Trump's and Biden's vote share in that forecast (thus disregarding third party candidates). Trump's actual share of the 2-party popular vote would be calculated in the same way, and the question resolves as the actual 2-party vote share minus the predicted 2-party vote share.

For example, suppose FiveThirtyEight shows 50% Biden and 40% Trump. Then Trump's vote share would be 40/90 = 44.4%. Now suppose the actual popular vote is 40 million Biden, 38 million Trump and 200 million Kanye West. Then the actual two-party vote share would be 38/78 = 48.7%. Thus, this question would resolve as 48.7-44.4 = 4.3. Conversely, if Trump's vote share was lower than FiveThirtyEight's prediction, the question would resolve as a negative value.

The forecast will be taken from the latest forecast on the day before the election, i.e. November 2. If FiveThirtyEight does not display a forecast at that time, or it has not been updated in more than a week, this question resolves ambiguous.

FiveThirtyEight's "popular vote" forecast is currently displayed on their 2020 election forecast page in a tab under the "How the forecast has changed" section. Should the formatting change, the forecast that displays this same information will be considered as the popular vote forecast. If there is ambiguity, the admins will decide what forecast is the reference forecast for this question.

If Donald Trump or Joe Biden cease to be their respective parties' nominees for the 2020 US presidential election, this question resolves as ambiguous.

{{qctrl.predictionString()}}

Metaculus help: Predicting

Predictions are the heart of Metaculus. Predicting is how you contribute to the wisdom of the crowd, and how you earn points and build up your personal Metaculus track record.

The basics of predicting are very simple: move the slider to best match the likelihood of the outcome, and click predict. You can predict as often as you want, and you're encouraged to change your mind when new information becomes available.

The displayed score is split into current points and total points. Current points show how much your prediction is worth now, whereas total points show the combined worth of all of your predictions over the lifetime of the question. The scoring details are available on the FAQ.

Note: this question resolved before its original close time. All of your predictions came after the resolution, so you did not gain (or lose) any points for it.

Note: this question resolved before its original close time. You earned points up until the question resolution, but not afterwards.

This question is not yet open for predictions.

Thanks for predicting!

Your prediction has been recorded anonymously.

Want to track your predictions, earn points, and hone your forecasting skills? Create an account today!

Track your predictions
Continue exploring the site

Community Stats

Metaculus help: Community Stats

Use the community stats to get a better sense of the community consensus (or lack thereof) for this question. Sometimes people have wildly different ideas about the likely outcomes, and sometimes people are in close agreement. There are even times when the community seems very certain of uncertainty, like when everyone agrees that event is only 50% likely to happen.

When you make a prediction, check the community stats to see where you land. If your prediction is an outlier, might there be something you're overlooking that others have seen? Or do you have special insight that others are lacking? Either way, it might be a good idea to join the discussion in the comments.