Forecasting the 2020 US Elections with Decision Desk HQ: Methodology for Modern American Electoral Dynamics

Optimus has constructed models to predict the outcomes of the 2020 presidential and congressional general elections in collaboration with Decision Desk HQ. The model is an iteration from its 2018 U.S. Congressional model designed to predict the outcome of the election as if it were held today. The congressional model predicts the probability of a Republican (GOP) victory in individual House and Senate elections, as well as the number of aggregate seats expected to be won by each party (to predict partisan control of each chamber). The presidential model uses a similar framework to estimate vote shares and probabilities of victory for each major party candidate in each of the states. These estimates are then used to proxy electoral college predictions that determine who is elected as the next President of the United States. We provide a survey of features, feature engineering techniques, models, and ensembling techniques. We also provide some empirical results.