The scientific forecast of the Bundestagswahl

We are a team of political scientists from the University of Mannheim, Witten/Herdecke University and Hertie School Berlin.

Our goal is to use our statistical model to provide a broad audience with information and forecasts about the federal election that go beyond the snapshots of political sentiment provided by opinion polls (e.g., “Sunday polls“).
Predictions of future events, in this case the outcome of the federal election, are always fraught with uncertainty. Therefore, it is particularly important to us to communicate the uncertainty of prediction models such as that of zweitstimme.org clearly and in a way that is easy to understand.
This information can help journalists, experts and citizens to better assess and communicate actual party support and ultimately make better-informed voting decisions.

Evaluation of Predictions: Comparing Model Forecasts and Actual Election Results

In this post, we evaluate the forecasts for the state elections in Saxony, Thuringia, and Brandenburg, which were published on our website, and compare them with the actual election results. The following text refers to the predictions that were published two days before the elections. Evaluation of the Forecasts Saxony The close race between the CDU and AfD in Saxony was narrowly won by the CDU. With 31.9%, the party’s vote share is 2.2% higher than the forecast two days before the election. The AfD improved to 30.6%, which is 0.9% lower than our prediction. ...

Forecast for the State Election in Brandenburg - 2 Days Before the Election

Two weeks ago, we published forecasts for the state election in Brandenburg. Today, two days before the election, we are updating these forecasts using our prediction model, based on the polls published in the meantime. Based on previous state elections from 2010 to 2023, we know that our forecasts two days before the election are already very accurate. We have an average absolute deviation of 1.46 percentage points across all parties, which is very close to the final result. ...

Forecast for the State Elections in Brandenburg

In two weeks, German state elections will be held in Brandenburg. We at Zweitstimme have now developed a forecasting model for state elections and are pleased to present our forecasts on this page, two weeks ahead of the elections – as we did for Saxony and Thuringia. The Forecast Brandenburg In Brandenburg, our current forecast shows a tight race between four parties: AfD, SPD, BSW, and CDU, all polling around 20%. For the SPD, which was the largest party in the last election, we expect 21.0% of the votes. However, our forecast two weeks before the election still allows for a 5/6 probability that this value will fall within the credibility interval of 15.8% to 26.6%. The AfD, on the other hand, is expected to significantly improve, and in our estimation, it might narrowly surpass the SPD with 24.3%. However, this interval also ranges from 18.5% to 30.5%. ...

Forecast for the State Elections in Saxony and Thuringia - 2 Days Before the Election

Two weeks ago, we published forecasts for the state elections in Saxony and Thuringia. Today, two days before the election, we are updating these forecasts using our prediction model, based on the polls published in the meantime for Saxony and Thuringia. Based on previous state elections from 2010 to 2023, we know that our forecasts two days before the election are already very accurate. We have an average absolute deviation of 1.46 percentage points across all parties, which is very close to the final result. ...

Forecast for the State Elections in Saxony and Thuringia

In two weeks, German state elections will be held in Saxony and Thuringia. We at Zweitstimme have now developed a forecasting model for state elections and are pleased to present our forecasts on this page, two weeks ahead of the elections. The Forecast Saxony In Saxony, our current forecast shows a close race between the CDU and the AfD. For the CDU, which was the largest party in the last election, we expect 30.0% of the votes. However, our forecast two weeks before the election still allows for a 5/6 probability that this value will fall within the credibility interval of 23.5% to 37.0%. The AfD, on the other hand, is expected to significantly improve, and in our estimation, it might narrowly surpass the CDU with 30.6%. However, this interval also ranges from 24.0% to 37.6%. ...