A Sharper discrepancy measure for post-election audits

TL;DR

This paper introduces a new discrepancy measure called maximum relative overstatement of pairwise margins (MRO) for post-election audits, providing a sharper and more accurate way to verify election outcomes especially with multiple candidates or voting methods.

Contribution

The paper proposes the MRO measure, which improves upon previous discrepancy metrics by offering a more precise test for election outcome validity in complex voting scenarios.

Findings

MRO provides a more sensitive test for election outcome discrepancies.

Application to Minnesota 2006 Senate race shows MRO yields a significant p-value.

MRO outperforms previous measures in detecting potential outcome errors.

Abstract

Post-election audits use the discrepancy between machine counts and a hand tally of votes in a random sample of precincts to infer whether error affected the electoral outcome. The maximum relative overstatement of pairwise margins (MRO) quantifies that discrepancy. The electoral outcome a full hand tally shows must agree with the apparent outcome if the MRO is less than 1. This condition is sharper than previous ones when there are more than two candidates or when voters may vote for more than one candidate. For the 2006 U.S. Senate race in Minnesota, a test using MRO gives a $P$-value of 4.05% for the hypothesis that a full hand tally would find a different winner, less than half the value Stark [Ann. Appl. Statist. 2 (2008) 550--581] finds.