Expert panel forecast: Democrats remain at 52.0%

The Pollyvote team has completed its third survey of elections experts to forecast the 2016 presidential election. In the late February survey, conducted between February 26 and 29, fifteen experts responded. The forecasts for the Democratic popular two-party vote ranged from a minimum of 48.5% to a maximum of 54.5%. The mean forecast was 52.0%.

This is the exact same result as in the previous survey conducted a month ago and also perfectly matches the latest combined PollyVote forecast.

Polly thanks the experts who participated in this round, namely

and one expert who preferred to remain anonymous.

Compute your own model forecasts

For some models, Polly now allows you to manipulate the variable values and compute your own model forecasts. For now, this is available for the Fair model and Lichtman’s Keys to the White House. Polly will soon add this functionality also for other models. Stay updated:

Revised forecast of Primary model

Helmut Norpoth provided an update of his Primary model forecast. The initial forecast posted on February 27 relied on a polling data, not actual results, for the Democratic primary in South Carolina. Now that the results are in, which give Hillary Clinton a much bigger lead than was indicated by the polls, the forecasts for the various general election match-ups are as follows:

Revised general election forecasts of the Primary model
Race Democratic vote Republican vote Probability of winning
Clinton-Trump 47.5 52.5 87%
Clinton-Rubio 52.4 47.6 86%
Sanders-Trump 42.3 57.7 99%
Sanders-Rubio 47.2 52.8 89%

At the moment, there are forecasts from five component methods, and five econometric models, available. Therefore, the primary model enters the combined PollyVote forecast with a current weight of 4%. Not surprisingly then, the PollyVote forecast is largely unaffected by this change and still predicts the Democrats to gain around 52.0% of the two-party vote.

Primary model predicts Trump victory

Polly added the Primary model by Helmut Norpoth to its econometric models component. The model is based on state electoral histories and candidates’ performance in early primaries.

Assuming a Clinton-Trump race, the model predicts a clear victory for the Republicans, with Donald Trump gaining 54.7% of the two-party vote (compared to 45.3% for Clinton). This is the largest lead for the Republicans in any forecast available to date. In other words, the forecast is an outlier. In comparison, today’s combined PollyVote forecast predicts the Democrats to gain 51.9% of the vote, compared to 48.1% for the Republicans.

New model added to econometric models

Polly added the long-range model by Jay DeSart to its econometric models component. The model is based on state electoral histories, national polling data as well as two variables that attempt to estimate next year’s election context.

Assuming a Clinton-Trump race, the model’s latest forecast predicts a close outcome, with a slight advantage for the Republicans. That is, the model predicts the Democrats to gain 49.3% of the national two-party vote, compared to 50.7% for the Republicans. In comparison, the latest PollyVote forecast forecasts a vote share of 52.0% for the Democrats and 48.0% for the Republicans.

Note: There was a minor mistake in calculating the combined econometric model forecast as a result of adding the DeSart model on February 12th. The effect on the combined PollyVote forecast was negligible, however. The error was corrected on February 15th.

Democrats gain after NH primary

The results of the New Hampshire primary might look good for Donald Trump’s prospects to win the Republican nomination. And yet, according to the PollyVote, the Democratic party is the real winner of yesterday’s election. As a result of Trump taking back the lead in the PredictWise GOP nomination forecast, PollyVote’s forecast of the Democratic two-party vote share in the general election has increased by 1.2 percentage points to currently 51.5% (vs. 48.5% for the Republicans). This is the largest lead for the Democrats since PollyVote published its first forecast on January 1st, 2016.

Experts still see Democrats in the lead

The Pollyvote team has completed its second survey of elections experts to forecast the 2016 presidential election. In the late January survey, conducted between January 26 and 30, 17 academics from a variety of colleges and universities responded. The mean forecast is that the Democrats will garner 52.0% of the major-party vote, compared to 48.0% for the Republicans. In the previous survey, conducted in late December, the experts had predicted a vote share of 51.7% for the Democrats and 48.3% for the Republicans. 

Polly thanks the experts who participated in this round, namely

  1. Randall Adkins (University of Nebraska Omaha)
  2. Lonna Rae Atkeson (University of New Mexico)
  3. Scott Blinder (University of Massachusetts Amherst)
  4. John Coleman (University of Minnesota)
  5. George Edwards (Texas A&M University)
  6. John Geer (Vanderbilt University)
  7. Sandy Maisel (Colby College)
  8. Michael Martinez (University of Florida)
  9. Thomas Patterson (Harvard University)
  10. Gerald Pomper (Rutgers University)
  11. David Redlawsk (Rutgers University)
  12. Larry Sabato (University of Virginia)
  13. Michael Tesler (University of California, Irvine)
  14. Charles Walcott (Virginia Tech)

as well as three experts who preferred to remain anonymous.

Experts give Democrats a slight edge

The Pollyvote team has completed its first survey of elections experts to forecast the 2016 presidential election. In the late December survey, conducted between December 26 and 31, eight academics from a variety of colleges and universities predicted that the Democrats will eke out a narrow victory over the Republicans. The mean forecast is that the Democrats will garner 51.7% of the major-party vote, compared to 48.3% for the Republicans.

The Pollyvote team will conduct similar surveys monthly until fall 2016, when the experts will be polled more frequently.

This is the fourth presidential election campaign in which an expert panel has been formed by the Pollyvote team to forecast the election outcome. The first surveys, those in 2004, did not begin as early as the current survey, but those for 2008 and 2012 did. In 2012, the late December survey revealed an average forecast of 50.6% for Obama, who eventually received 52% of the two-party vote; a forecast error of merely 1.4 percentage points. In 2008, the late December survey predicted McCain to gain 47.7%. Again, this long-term forecast was off by only 1.4 percentage points, as McCain eventually won 46.3% of the vote. Thus, even with this long lead time, the expert panelists were able to forecast the winner in both elections. As we see, the experts have considerable expertise in forecasting elections. Watch this space for the next report from the experts in about a month.

Correction note: A previous version of this article incorrectly stated that the mean expert forecast was 51.9% for the Democrats and 48.7% for the Republicans.

First PollyVote forecast predicts close race

Today, the PollyVote published its first forecast for the 2016 election. Her first forecast of the national popular two-party vote predicts a virtual tie, with the Democrats at 50.1%, and the Republicans at 49.9% of the vote.

The PollyVote first started in 2004 by political scientists and forecasting experts and has accurately forecast US presidential elections since then. For details about the procedure as well as historical data, see the published research or read the FAQ.

We will have some exciting additions to the PollyVote in 2016. Stay tuned!