Seeing the Forest for the Trees: Presidential Election Forecasts and the Fundamentals by James E. Campbell
Modern presidential election campaigns generate a massive amount of news. This has never been more true than for this year’s campaign, an especially intense open-seat election campaign conducted with the parties near parity, with both an electorate and party system highly polarized, and with a pair of highly controversial and generally not-well-thought-of contenders. Every twist and turn, real and imagined, is reported and exhaustingly scrutinized. Even dedicated political junkies may feel overwhelmed by the hourly onslaught of election information as the political world churns.
The truth is that the vast amount of information pouring out of campaigns and developed by campaign watchers is of little or no consequence to the election’s outcome. It is noise — distracting and sometimes interesting noise, but nonetheless noise. In this din of information, the important aspects of the elections are often lost or overshadowed. This is where election forecasting models can help refocus attention on what matters, what the election may truly hinge on, what the campaigns may want to work on, and what we should expect in November when the votes are counted.
The modern era of election forecasting began in the mid-1980s. Since then, the number of models has grown (including those outside of academia). Experience has led to some models being tinkered with, some significantly revised, and others junked. Every model is different, but all are based on statistical analyses of how different pre-campaign contexts (“the fundamentals”) have translated into the two-party popular vote divisions in past presidential elections. Each forecast indicates what we should expect the vote to be. None expects perfection. The models themselves are imperfect. They use imperfect data. And then, apart from campaign effects that might be expected by the election’s context, some unexpected developments always make a difference. On occasion, some campaign news is not merely noise. Though imperfect and though accuracy varies from one model to the next and one election to the next, the models overall were quite accurate last time out. In the 2012 election, four of the forecasts were within one percentage point of the vote and another three were within two points.
James E. Campbell has been publicly forecasting presidential elections since 1992. He is a UB Distinguished Professor at the University at Buffalo, SUNY and the author of the new book, Polarized: Making Sense of a Divided America (Princeton, 2016).