Elections Performance Index

About the EPI

The Elections Performance Index (EPI), first launched in 2013 by The Pew Charitable Trusts, provides a non-partisan, objective measure of how well each state is faring in managing national elections. Using indicators that span the breadth of election administration, the index can show the impact of policy changes as well as where a state might be doing well or facing challenges. It’s an important resource for election officials, voters, and policymakers, allowing them to compare their state with its own past performance or the performance of other states.

In 2016, the MIT Election Data & Science Lab took over management of the EPI. We are proud to launch its newest iteration on a brand new website:

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Election Management in the U.S. is Improving

(PDF available here)

CAMBRIDGE, MA, August 9 — States’ administration of elections overall improved by 6 percentage points between 2012 and 2016, according to the Elections Performance Index released today by the Election Data & Science Lab at the Massachusetts Institute of Technology (MIT).

The index, which was initially managed by The Pew Charitable Trusts before being transferred to the MIT Election Lab in 2017, provides a nonpartisan, objective measure of how well each state is faring in managing national elections. Using indicators ranging from wait times at the polls and voter turnout to problems with absentee ballots, voter registration, or voting technology, the study can show the impact of policy changes and where a state might be doing well or is facing challenges. Voters, policymakers, and election officials can use its rankings to compare their state with its own past performance, as well as the performance of other states.

“The index is an important foundation for the ongoing discussions on election management,” said Charles Stewart III, the Kenan Sahin Distinguished Professor of Political Science at MIT and founding director of the MIT Election Lab. “The new release of the index helps remind us that election administration is a multi-dimensional challenge. Significant improvements in the 2016 index also illustrate that when election officials commit themselves to a path of improvement, good things can happen.”

Overall, almost all states improved their index scores in the 2016 presidential election, compared with 2012. Twenty-two states improved at a rate greater than the national average. Overall, Vermont showed the most significant improvement, landing at the top of the index for the first time after expanding the availability of online tools, providing online voter registration, and requiring a post-election audit.

Only six states saw their scores decline from 2012. This is largely due to an increase in the residual vote rate, which is a common measure of voting machine performance. However, the residual vote rate can also increase when more voters abstain from voting for president, which appears to have been a significant factor in the decline of four of these six states.

Some of the trends demonstrated in the 2016 index include the following:

  • Growing reliance on online resources. Between 2012 and 2016, the number of states offering voters the chance to register online grew from 13 to 33. The number allowing voters a chance to update their existing registration, rather than enter a new registration, grew from zero to four.
  • Improvement in wait times. In 2016, no state had an average wait-time to vote of over 20 minutes, down from seven states in 2012. One of the clearest examples of this change can be seen in Florida, which experienced an average voting wait time of 45 minutes in 2012, and saw that average plummet to only 5.5 minutes in 2016.
  • Increasing use of post-election audits. Thirty-five states required some form of post-election audit to check vote totals in 2016, up from 31 in 2012.
  • Decline in reported registration problems. Fewer eligible voters cited registration problems as a reason for not voting in 2016 (only 13.9% nationwide) than in 2012 (15.7%).
  • Decline in problems encountered by voters with disabilities. Many fewer eligible voters cited disability or illness as a reason for not voting in 2016—the rate was 5.7%, which is down from 6.7% overall in 2012.
  • Improvement the process of military and civilian overseas ballots. Ballots from military and civilian overseas voters were more likely to be returned in 2016 than in 2012. The ballots that were returned were also more likely to be counted. Overall, the rate of non-return for military and overseas ballots fell from 29.9% to 25.5% from 2012 to 2016, while the percentage of such ballots that were accepted for counting rose, from 94.3% to 96.4%.

The newest release of the index brings the data up-to-date to the 2016 election.

Because updates depend on statistical reports from the U.S. Election Commission that are are not released until the summer following each federal election, the next update, with data from the upcoming 2018 midterm election, is slated for late 2019 or 2020. This necessary delay between updates means that the current release often does not reflect new concerns. For example, concerns about voter fraud, voter list maintenance, and election security that arose in 2016 and are currently the focus of policy debates do not feature in the current index. They could, however, be included in future iterations, as academics and officials further refine what can and should be measured to gauge the health of U.S. elections.

To view the Elections Performance Index and explore the 2016 data, visit

This image shows a colorcoded map displaying the scores of each state on the 2016 EPI

About the MIT Election Data & Science Lab

The MIT Election Data & Science Lab supports advances in election science by collecting, analyzing, and sharing core data and findings. We aim to build relationships with election officials and others to help apply new scientific research to the practice of democracy in the United States. Learn more about our work here.

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Claire DeSoi, Communications & Outreach