A number of states have enacted requirements for mandatory manual audits (in randomly selected precincts) of the voter-verified paper records produced by the voting systems in use in those states. These audits are designed to verify that the electronic voting systems (either DRE voting machines or optical scan voting systems) are accurately recording and counting the votes. In the randomly-selected precincts, a hand count of the voter-verified paper records is compared to the totals reported by the electronic voting system. (Click on the map to see which states require post election audits.)
Two states without voter-verified paper record requirements (Kentucky, Pennsylvania) also have audit requirements. These were written into statute decades ago, apparently prior to widespread adoption of (paperless) direct recording electronic (DRE) voting systems. It is unclear whether – or how – these states are carrying out their statutory audit requirement. Texas requires audits of optical scan paper ballot systems only; counties with DREs have no voter-verified paper records to audit. The audit provisions in the various states illustrate a variety of manual audit requirements in several states using voter verified paper records, as well as two provisions from states that do not (yet) require VVPR. Some apply generically to both direct recording electronic systems equipped with voter-verified paper audit trails (VVPAT) and optical scan systems, since both offer voter-verified paper records which can be compared to an electronic tally. Others refer specifically to DRE + VVPAT systems (e.g. Washington). In every case (except Kentucky and Pennsylvania) the paper record verified by the voter is the one used in the manual count. The quantity of ballots to audit is most often stated as the ballots in some percentage of the total precincts, although some provisions audit by other units (by machine, ballot batches, etc.).
Well-designed and properly performed post-election audits can significantly mitigate the threat of error, and should be considered integral to any vote counting system. A post-election audit in this document refers to hand-counting votes on paper records and comparing those counts to the corresponding vote counts originally reported, as a check on the accuracy of election results, and resolving discrepancies using accurate hand counts of the paper records as the benchmark. Such audits are arguably the most economical component of a quality voting system, adding a very small cost2 for a large set of benefits.
The benefits of such audits include:
- Revealing when recounts are necessary to verify election outcomes
- Finding error whether accidental or intentional
- Deterring fraud
- Providing for continuous improvement in the conduct of elections
- Promoting public confidence in elections
Post-election audits differ from recounts. Post-election audits routinely check voting system performance in contests,3 regardless of how close margins of victory appear to be. Recounts repeat ballot counting in special circumstances, such as when preliminary results show a close margin of victory. Post-election audits that detect errors can lead to a full recount.
When an audited contest is also recounted, duplicate work can be avoided. Voting systems should have reliable audit records. Best effort audits should be performed even if the technology does not support optimal audits, or even if the laws do not permit optimal remedies. No single model for post-election audits is best for all states. Election traditions, laws, administrative structure and voting systems vary widely. Nonetheless, there are guiding principles that apply across all states. As states develop their own audit models, the public should have the opportunity to help shape those regulations.4
All states should look to statistical sampling methods tied to the margin of victory to improve their criteria for how many units to audit for more effective auditing. A well designed audit can provide a large chance of correcting the outcome if it was wrong. Such risk-limiting audits are being piloted in California, Colorado and Ohio; Colorado law requires moving to risk-limiting audits by 2014. Currently only North Carolina legally requires the use of statistical methods in the selection process, while Oregon, New Mexico and New Jersey laws require taking the margin of victory into account when determining what (fixed) percentage to audit. (New Jersey’s law is not yet implemented). Ten California counties conducted pilot risk-limiting audits recently. Among other state grants, the U.S. Election Assistance Commission awarded California $230,000 in federal grant money to fund up to 20 such pilot audits following elections held in California counties throughout 2012.
The following steps are critical for a good audit:
Auditing All Ballots Good audit protocols mandate that all ballots – early and absentee ballots, UOCAVA ballots, regular and provisional ballots, and aggregation at the tally server – be audited for accuracy.
Using Transparent and Random Selection Processes for All Auditing Procedures Audits are much more likely to prevent fraud, and produce greater voter confidence in the results, if the ballots, machines or precincts to be audited are chosen in a truly random and transparent manner, observable by the public with sufficient notice.
Conducting in a Timely Manner Audits should be conducted before results are finalized, so that if the audit reveals problems, official totals can be corrected.
Implementing Effective Procedures for Addressing Evidence of Fraud or Error If audits are to have a real deterrent effect and catch widespread, systemic problems, jurisdictions must adopt clear procedures for dealing with audit discrepancies when they are found.. Such procedures must ensure that outcome-changing errors are not ignored, otherwise vote tampering succeeds.
Encouraging Rigorous Chain of Custody Practices. Audits of voter-verifiable paper records will deter attacks and identify problems only if states have implemented solid chain of custody and physical security practices that will allow them to make an accurate comparison of paper and electronic records.
|Ron Rivest at the 2007 Post Election Audit Summit||Joe Hall speaking at the 2007 Post-Election Audit Summit|
- For example, in Pottawattamie County, Iowa, in the June 2006 primary election for County Recorder, the original optical scan count showed challenger Oscar Duran defeating the incumbent, John Sciortino. A hand count showed that Sciortino actually had won handily; the scanners had been misprogrammed. In Napa County, California, after the March 2004 primary, the 1% manual tally discovered that the optical scanners had been miscalibrated and were failing to detect the dye-based ink commonly used in gel pens. The ensuing recount recovered almost 6700 votes (but no outcomes changed). ↩
- For instance, in Minnesota after the 2006 general election, the cost of the wages for election judges (pollworkers) to count votes has been estimated at $24,500 to $27,000 statewide – 9 to 10 cents per hand-counted vote, and about 1.2 cents per voter in the election (http://www.ceimn.org/files/CEIMNAuditReport2006.pdf). While audit costs will vary depending on the scope of the audits and other considerations, they can be expected to be a small fraction of election administration costs. ↩
- We use “contest” to refer to any ballot item (such as an election to public office or a ballot initiative) – not to a challenge to the results, as in some states. ↩
- From ElectionAudits.org ↩
- Douglas W. Jones and Barbara Simons, Broken Ballots, 2012, pp. 336-338. ↩
- American Statistical Association. 2010. Statement on risk-limiting post-election audits, http://www.amstat.org/outreach/pdfs/Risk-Limiting_Endorsement.pdf Apr. 17, 2010. ↩
- Stark, Philip B. 2010. Risk-limiting vote-tabulation audits: The importance of cluster size. Chance 23(3): 9-12. ↩
- Colorado, State of. 2009. x 1-7-515: Risk limiting audits – pilot program. Col. Revised Statutes, Title 1, Article 7, Part 5. Originated as House Bill 09-1335, Section 12. ↩
- California, State of. 2010. x 15560: Post-canvass risk-limiting audit pilot program. Cal. Elections Code, Div. 15, Chapt. 8.5. Jul. 19, 2010. Originated as Assembly Bill 2023. ↩