Electoral forecasting using a novel temporal attenuation model: Predicting the US presidential elections

•A new model for multi-opinion systems targeting better election forecasting.•Temporal attenuation (TA) models opinion momentum from pre-election polls.•Validation on US Presidential elections datasets from 1968 to 2016.•TA achieves 23–37% higher forecasting performance than state of the art.•Our method works without the need for social-economical indices. Electoral forecasting is an ongoing scientific challenge with high social impact, as current data-driven methods try to efficiently combine statistics with economic indices and machine learning. However, recent studies in network science pinpoint towards the importance of temporal characteristics in the diffusion of opinion. As such, we combine concepts of micro-scale opinion dynamics and temporal epidemics, and develop a novel macro-scale temporal attenuation (TA) model, which uses pre-election poll data to improve forecasting accuracy. Our hypothesis is that the timing of publicizing opinion polls plays a significant role in how opinion oscillates, especially right before elections. Thus, we define the momentum of opinion as a temporal function which bounces up when opinion is injected in a system of voters, and dampens down during states of relaxation. We validate TA on survey data from the US Presidential Elections between 1968 and 2016, and TA outperforms several statistical estimates, ARIMA models, as well as the best pollsters at their time, in 10 out of 13 presidential elections. We present two different implementations of the TA model, which accumulate an average forecasting error of 3.04 points over the 48-year period. Conversely, statistical methods accumulate 7.48 points error, and the best pollsters accumulate 3.64 points. Overall, TA offers increases of 23–37% in forecasting performance compared to the state of the art. We show that the effectiveness of TA does not drop when relatively few polls are available; moreover, with increasing availability of pre-election surveys, we believe that our TA model will become a reference alongside other modern election forecasting techniques.