1 design, findings, and lessons learned: sample audit recounts in 2006 north carolina elections...
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Design, Findings, and Lessons Learned: Sample Audit Recounts in
2006 North Carolina Elections
William D. KalsbeekLei Zhang
University of North Carolina, Survey Research Unit, Department of Biostatistics
E-mail: [email protected]
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Background
• The NC Board of Elections asked the UNC Survey Research Unit (SRU) to design and conduct an election recount audit for 2006 primary and general elections
• A 2006 bill passed by the NC Legislature now mandates that a “ hand-to-eye” recount be done for national/statewide offices in each election– Little mention of how the recount data are to be analyzed
• Recounts completed thus far:– May 2006 primary – State supreme court associate justice
seat (five candidates)– November 2006 general election – State supreme court
chief justice seat (two candidates)
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Sampling Precincts/Places
• Stratified random sample precincts/places – NC has 3,047 precincts/places overall– 100 counties as strata (sampling in each
county required by NC-BOE)– Total precinct/place sample sizes:
• n = 200 (6.6%) for May primary election – 2 per county
• n = 264 (8.7%) for November general election – 2 or more per county– More than 2 to the extent of May discrepancies)
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Recounting the Votes
• Selected precincts/places announced after each election
• Bi-partisan recount:– Generally followed hand-count procedures– Teams of 3-4 from each political party– Team members rotate duty as “tallier” and
“caller”
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Two Types of Vote Count Discrepancies in Precincts/Places
• Discrepancy in Candidate Count (DCC)– In vote count for each candidate on ballot– Discrepancy = [Election Count] – [Recount]
• Discrepancy in Total Count (DTC)– In total vote count for all candidates– Discrepancy = [Election Count] – [Recount]
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Discrepancies at Each Precinct/Place
ELECTION:
Candidate
E1 E2E3
E4 ___________ Total E Count
RECOUNT:
Candidate
R1 R2R3
R4 ___________ Total R Count
All DCC Discrepancies
DTC Discrepancy
7TABLE 1Estimated % Distribution of DTCs Among All Precincts/Places
for Five Statewide Candidates in May 2006 PrimarySupreme Court Associate Justice (Wainwright Seat)
FINDINGS: •Total votes reported in the election = 519,615• Range of DTCs: -4 to +4 • Over-count vs. under-count: favors undercount somewhat• Discrepancies much less likely for iVotronic than M100
Value of DTC
Type of Machine Used in Precinct/
Place -4 -3 -2 -1 0 1 2 3 4
Precinct/Place
Sample Size
All Machines Combined 0.2 1.2 0.8 10.5 82.6 2.4 1.0 1.0 0.3 195
M100 Machines Only 0.3 1.7 1.2 12.5 79.5 2.0 1.0 1.4 0.4 150
iVotronic Machines Only 5.2 90.5 3.3 1.0 48
8TABLE 2Estimated % Distribution of All DCCs Among All Precincts/Places
for Five Statewide Candidates in May 2006 Primary Supreme Court Associate Justice (Wainwright Seat)
FINDINGS: •Total votes reported in the election = 519,615• Range of All DCCs: -2 (undercount) to +3 (overcount)• Overall over-count vs. under-count -- very slightly favoring undercount• Discrepancies equally rare for iVotronic and M100
Value of DCC
Type of Machine Used in
Precinct/ Place -4 -3 -2 -1 0 1 2 3 4
Precinct/ Place
Sample Size
All Machines Combined 0.18 3.04 95.00 1.68 0.02 0.04 195
M100 Machines Only 0.26 3.86 93.88 1.90 0.04 0.04 150
iVotronic Machines Only 1.04 97.90 1.06 48
9TABLE 3Estimated % Distribution of DTCs Among All Precincts/Places for
Two Statewide Candidates in November General Election Election for State Supreme Court Chief Justice
FINDINGS: • Total reported votes = 1,707,326; 2 to 1 margin of victory = 569,366• Range of DTCs --- mostly -13 to +13 • Discrepancies of this type are more likely than in May primary • Over-count vs. under-count: slightly favors undercount• Discrepancies much less likely for iVotronic than M100
Value of
DTC
Type of Machine Used in
Precinct/ Place -13 -9 -3 -2 -1 0 1 2 3 10 13 172
Precinct/ Place
Sample Size
All Machines Combined 0.15 0.03 1.30 4.39 10.89 80.16 1.48 0.15 1.06 0.22 0.04 0.13 264
M100 Machines Only 0.21 0.05 1.85 6.28 15.57 73.46 1.66 0.66 0.66 0.19 205
iVotronic Machines Only 96.29 0.93 0.43 1.72 0.64 67
10TABLE 4Estimated % Distribution of All DCCs Among All Precincts/Places for
Two Statewide Candidates in November 2006 General Election Election for State Supreme Court Chief Justice
FINDINGS: •Total election votes = 1,707,326 ; 2 to 1 margin of victory = 569,366• Range of All DCCs: mostly -14 to +12; with outlier at +86 • Discrepancies of this type are more likely than in May primary • Overall over-count vs. under-count: slightly favors undercount• Discrepancies much less likely for iVotronic than M100
Type of Machine
Value of
DCC
Precinct/
Used in Precinct/
Place -14 -8 -5 -3 -2 -1 0 1 2 3 5 6 7 12 86
Place Sample
Size
All Machines Combined 0.02 0.08 0.08 0.48 2.77 7.44 84.88 3.35 0.33 0.30 0.02 0.02 0.02 0.11 0.13 264
M100 Machines Only 0.03 0.11 0.11 0.69 3.81 10.64 79.46 4.56 0.36 0.03 0.03 0.03 0.19 205
iVotronic Machines Only 0.32 97.83 0.47 0.22 0.32 67
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Summary of Key Findings• May primary and November general election:
DTCs and DCCs in precincts/places – Both + (indicating overcount) and - (indicating
undercount) – Slightly favoring – (undercount)
• Greater discrepancies in November general election than May primary – >3 time as many votes cast in November
• Greater discrepancies (in both directions) in precincts/places using M100 voting machines than in those using IVotronic machines
12Lessons Learned in Conducting North Carolina Election Audits
• Sampling– Must be random– What do we need to learn from an audit? Sample
design must be responsive to this.– Drop county focus?– Sample more intensively where there has been disparity– Sample locations not announced until after the election
• Data gathering– Recounting should be “blinded” to election count– Think about other practical ways to make the recount a
better gold standard– Expect a few process “glitches”
