Post-Election Audits: Restoring Trust in Elections

With the intention of assisting legislators, election officials and the public to make sense of recent literature on post-election audits and convert it into realistic audit practices, the Brennan Center and the Samuelson Law, Technology and Public Policy Clinic at Boalt Hall School of Law (University of California Berkeley) convened a blue ribbon panel (the "Audit Panel") of statisticians, voting experts, computer scientists and several of the nation's leading election officials. Following a review of the literature and extensive consultation with the Audit Panel, the Brennan Center and the Samuelson Clinic make several practical recommendations for improving post-election audits, regardless of the audit method that a jurisdiction ultimately decides to adopt

Post-election audits: statistical power based methods and a trigger for further auditing

Two important components of an audit procedure are the sample size and the decision rule for expanding the audit. This paper describes a method for determining the audit size that ensures a high probability of detecting miscounts if election-altering ones exist. Then, two possible “triggers” for further auditing are developed: a modified bootstrap confidence interval and a modified Hoeffding bound. Both estimate the net gain in votes for the originally reported loser if a full audit were conducted. In simulations, both methods maintained high power for various miscount situations, with the Hoeffding bound having slightly lower false positive rates

Conservative statistical post-election audits

There are many sources of error in counting votes: the apparent winner might not be the rightful winner. Hand tallies of the votes in a random sample of precincts can be used to test the hypothesis that a full manual recount would find a different outcome. This paper develops a conservative sequential test based on the vote-counting errors found in a hand tally of a simple or stratified random sample of precincts. The procedure includes a natural escalation: If the hypothesis that the apparent outcome is incorrect is not rejected at stage $s$, more precincts are audited. Eventually, either the hypothesis is rejected--and the apparent outcome is confirmed--or all precincts have been audited and the true outcome is known. The test uses a priori bounds on the overstatement of the margin that could result from error in each precinct. Such bounds can be derived from the reported counts in each precinct and upper bounds on the number of votes cast in each precinct. The test allows errors in different precincts to be treated differently to reflect voting technology or precinct sizes. It is not optimal, but it is conservative: the chance of erroneously confirming the outcome of a contest if a full manual recount would show a different outcome is no larger than the nominal significance level. The approach also gives a conservative $P$-value for the hypothesis that a full manual recount would find a different outcome, given the errors found in a fixed size sample. This is illustrated with two contests from November, 2006: the U.S. Senate race in Minnesota and a school board race for the Sausalito Marin City School District in California, a small contest in which voters could vote for up to three candidates.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS161 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Post-Election Audits in the Philippines

How do you observe the unobservable? The election technology in use in the Philippines are optical ballot scanners called Vote Counting Machines (VCMs) that scan, count, and transmit election results at the close of polls back to the national tallying center. Postelection audits called Random Manual Audits (RMAs) are required by law to take place prior to the result becoming final. In this paper, we explore the idea of replacing RMAs by Risk-Limiting Audits (RLAs) that are effcient, have a high chance of correcting an incorrect election outcome by the means of a recount, and can therefore strengthen public confidence in the election

On Estimating the Size and Confidence of a Statistical Audit

We consider the problem of statistical sampling for auditing elections, and we develop a remarkably simple and easily-calculated upper bound for the sample size necessary for determining with probability at least c whether a given set of n objects contains b or more “bad” objects. While the size of the optimal sample drawn without replacement can be determined with a computer program, our goal is to derive a highly accurate and simple formula that can be used by election officials equipped with only a simple calculator

Mandatory Vote Count Audit

Voters, candidates, citizens and election officials want high confidence in the integrity of the election process by subjecting electronic vote counts to independent manual audits; and by making reports available with which to evaluate rates of voter turnout, voting equipment allocation, under-votes, over-votes, spoiled ballots, voting equipment failure, absentee ballots, uncounted ballots, and provisional ballots. This bill requires routine independent audits of vote count accuracy and requires the release to vote count auditors of records and information necessary to verify the integrity of the vote count audits and to evaluate voter service levels

Auditing the Election Ecosystem

Election administration is a highly complex process that involves multiple actors all working to achieve the goal of running an effective election. One critical technique for gathering the performance data needed to improve election management is through comprehensive evaluations, which we refer to as election ecosystem audits (EEA). These audits are evaluations of an election from start to finish. Accomplishing this goal requires election officials coordinating the efforts of contractors—from ballot printers to voting machine companies—third parties, like the US Postal Service who transport absentee ballots and the entities who agree to house polling places, and the poll workers who actually implement the election at the polls. Managing this vast enterprise requires election officials to evaluate their election activities so that they can improve the implementation of the process over time