Whose Votes Count? Undervotes, Overvotes, and
Ranking in San Francisco’s
Instant-Runoff Elections
Francis Neely,
Assistant Professor
Department of
Political Science
1600 Holloway Ave. HSS 263
San Francisco State
University
San Francisco, CA 94132
fneely@sfsu.edu
Corey Cook, Assistant
Professor
Department of
Politics
University of San Francisco
2130 Fulton St.
San Francisco, CA 94117
cdcook2@usfca.edu
ABSTRACT
We examine the first 3 years of San Francisco’s instant-runoff voting (IRV) elections
to determine whether some voters adapt more easily than others to the more
complex ballot and decision task. We draw on studies of uncounted votes to
develop hypotheses about tendencies to undervote, overvote, and rank candidates in IRV elections. Individual
ballot records and precinct-level census data are used to estimate the relative
influences of demographic and election-specific factors. A natural experiment
tests whether or not prior experience with IRV makes a difference. The change
to IRV appears to have increased the rate of overvotes
and decreased tendencies to undervote. Both behaviors
are explained by demographics and aspects of the electoral environment. Meanwhile,
tendencies to rank candidates were shaped less by demographics and more by
contextual factors and prior exposure to IRV. The findings extend the
literature on uncounted votes, inform issues of equality in elections, and
provide practical insights on this type of electoral reform.
Keywords: election reform; instant runoff; IRV; undervote; overvote; uncounted
votes; residual vote