2023 Risk-Limiting Audit

Yesterday, the Virginia Department of Elections randomly chose a legislative race, Senate District 20, as the contest to be audited as part of the post-election Risk-Limiting Audit (RLA) required by Virginia law. Electoral Boards in the counties of Arlington, Loudoun and Orange requested to also conduct RLAs of countywide offices in their jurisdictions.

Virginia implemented RLAs in 2018 to ensure that machine-tabulated results are consistent with what a full hand count of ballots would reveal. In 2022, Virginia changed the law to require that RLAs take place before election results are certified by the State Board of Elections.

What is a Risk-Limiting Audit?

At its simplest level, an RLA is a hand count of a random sample of voted ballots to identify any significant errors and provide evidence that the originally reported outcome of the election is correct. While there are different methods that can be used for an RLA, they all share a few key features:

1. Random Selection of Ballots - Ballots, or groups of ballots, must be selected at random so that all ballots have an equally likely chance of being audited.
2. Statistically Significant Sample Size - The number of ballots audited must be enough to ensure a statistically significant result; reviewing more ballots when needed in close contests, and fewer ballots in contests with wider margins.
3. Hand Count of Selected Ballots - The sampled ballots must be reviewed by a bipartisan team of poll workers and must be hand counted to identify if any errors were caused by voting machines.
4. Comparison of Hand Count and Machine Results - The hand-tallied results from the audited ballots are compared to results from the voting equipment.
5. Risk Limit Must Be Met - A statistical confidence level, the risk limit, is chosen in advance to determine how many ballots must be audited and the tolerance level for discrepancies. Virginia has set a risk limit of 10% for all RLAs. This means that there is a chance of 10% or less that an error in the outcome of the election would remain undetected by the audit. If the risk limit is not met, a larger sample of ballots must be counted until the risk limit is met, or the entire election has been counted by hand.

It is important to note that the purpose of the RLA is to ensure that the final outcome of the election is correct. Since Virginia began using RLAs, none of the audits have found errors that changed the outcome of an election.

What Happens Next?

The RLA will take place in the chosen district over the next two weeks and must be completed before the December 4th meeting of the State Board of Elections to certify results. If enough errors are discovered that the audit fails to meet the 10% risk limit, the hand count will be expanded until the results can provide the required level of statistical confidence in the reported outcome, or until all votes are recounted by hand. If a total hand recount is required, the results of the hand tally will be submitted for certification in place of the voting machine tabulation.

This same process will take place after every November election. In 2024, a statewide race will be audited, either for the U.S. Senate or U.S. President, along with one U.S. House of Representatives race.

Sources: Virginia Dept. of Elections, Risk Limiting Audit Manual. Code of Virginia § 24.2-671.2.