Early Voting as a Method of Predicting Elections

Emily, Ben, Will, Hallie

Early Voting History: Any ballot that is cast in the early voting period is what we consider early voting. To early vote some states mandate an excuse whereas states, like California, have a no-excuse absentee policy. In 1995 Oregon adopted the system by administering a federal primary election via mail. After Senator Bob Packwood was found guilty on charges of sexual harassment, mailing was the most effective way to host an impromptu election. Also with issues like Florida’s “hanging chad” of 2000, early voting helped to mitigate the pressure on election officials to process a massive influx of ballots quickly.


Although early-voting policies are regulated on the state level, with places like the Northeast that have particularly stringent laws, there is a growing trend of early voting, which creates a large sample size of data that isn’t expensive because voting is public information. Also, since they are votes and not polled information, those ballots actually impact the election, thus social desirability bias and non-attitudes are mitigated.


  • argument for using early voting as a predictor using past data


In 2008 and 2012, however, data from states where early and absentee votes accounted for more than 10 percent of the eventual vote total did prove to be a good predictor of the presidential election. In an analysis by the Washington Post, early voting did nearly as well in predicting 10 days before the election as it did the day before.


R2 (10 days out)=0.8

R2 (1 day out)=0.82


The lines represent Obama’s vote share as predicted by early and absentee votes, plotted against the percentage of early and absentee votes that were submitted by registered Democrats. The state abbreviations represent the actual final vote share that Obama received from that state. If a state falls below the line, then early voting data overestimated Obama’s final vote share; if a state falls above, early voting underestimated Obama’s final vote share. The lines in the plots for both cycles follow the general pattern of the results, and in 2008 the percentage of early or absentee votes for Obama explained 80% or more of the variance in the data (no R2 values were provided for 2012).

While these plots are promising, the accuracy of early voting as a predictor depends on how much of the final vote comes from early votes. If only a little amount of a state’s votes are submitted early, it is difficult to predict how the rest of the state will act on election day.

Hutch: Argument against using early voting as a predictor using past data




Early voting is far from predictive. FiveThirtyEight suggests that if polling is done right, it will take early voting into account and mark early voters as “likely voters”. This way polls take into account voters who have decided their vote well before the election, and any bumps in a candidate’s lead should be expected from early voting, not used as an indicator. The graph below shows from 2012 how some states, especially North Carolina, a crucial swing state, can mislead final results.


Research has shown that early voters are the most polarized, pre-decided voters who are most likely voting along party lines. Given this, early voting shouldn’t be an indicator of who will win a state in the electoral college. This creates an even greater unknown on actual election day.

RealClearPolitics writes, “[So basically, were left] without knowing how the Election Day electorate is likely to vote, and without knowing the size of the Election Day electorate. More importantly, we don’t know the effect to which campaign strategy is creating the appearance of a participation surge by merely cannibalizing Election Day voters by mobilizing voters who would have voted on Election Day anyway. This is a problem.” Ultimately, early voting does not take into account the actions and campaigns of candidates in the days leading up to the election, undecided voters, unlikely voters, and voter turnout. This is why early voting results should not be taken seriously as an indicator of final electoral results.

In this election, early voting was not a good predictor of the final outcome.



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s