[EM] The original Science Article

Alexander Small asmall at physics.ucsb.edu
Tue Jan 15 10:59:22 PST 2002

I'm subscribed to the digest version, so if somebody has already posted
it I apologize for the repetition.

Alex Small

Here it is:

It comes as a surprise to some that there is a science of elections. Its
provenance can be traced back to the Marquis de Condorcet in 18th-century
France, Charles Dodgson (Lewis Carroll) in 19th-century England, and
Kenneth Arrow in 20th-century America. Since Arrow published his seminal
book Social Choice and Individual Values 50 years ago--for which in large
part he received the Nobel Memorial Prize in Economics in 1972--there
have been thousands of articles and hundreds of books published on
everything from the mathematical properties of voting systems to
empirical tests of the propensity of different systems to elect centrist

The 2000 U.S. presidential election highlighted, among other things, the
frailties of voting machines and the apparent arbitrariness of such
venerable institutions as the U.S. Electoral College and Supreme Court.
Political commentary has focused on these aspects, but it has paid very
little attention to alternative voting systems, about which the science
of elections has much to say.

Several alternative systems for electing a single winner have been shown
to be far superior to plurality voting, our current system. Plurality
voting, which allows citizens to vote for only one candidate, suffers
from a dismaying flaw. In any race with more than two candidates,
plurality voting may elect the candidate least acceptable to the majority
of voters. This frequently happens in a three-way contest, when the
majority splits its votes between two centrist candidates. Plurality
voting also forces minor- party candidates into the role of spoilers, as
we saw in 2000, which can be decisive in a close contest between two
major-party candidates.

Of the alternatives to plurality voting, we recommend approval voting on
both practical and theoretical grounds. Approval voting allows voters to
vote for as many candidates as they find acceptable. For instance, one
can approve of a minor-party favorite and at the same time vote for an
acceptable major-party candidate. There is no ranking; the candidate with
the most approval votes wins, ensuring that the winning candidate is
acceptable to the largest fraction of the electorate.

Systems that involve ranking candidates may appear, at first blush, more
appealing than approval voting. One, the Borda count, awards points to
candidates according to their ranking. Another is the Hare system
(sometimes called "instant runoff"), in which candidates receiving the
fewest first-choice votes are progressively eliminated and their votes
transferred to second choices (and lower choices if necessary), until one
candidate emerges with a majority. Compared with approval voting, these
systems have serious drawbacks. The Borda count fosters "insincere
voting" (for example, ranking a second choice at the bottom if that
candidate is considered the strongest threat to one's top choice) and is
vulnerable to "irrelevant candidates" who cannot win but can affect the
outcome. The Hare system may eliminate a centrist candidate early on and
thereby elect one less acceptable to the majority. It also suffers from
nonmonotonicity, in which voters, by raising the ranking of a candidate,
may actually cause that candidate to lose.

Because approval voting empowers voters to express their political
judgments more fully, it should induce more citizens to go to the polls,
particularly in those early primary elections that determine the serious
contenders. It allows minor-party candidates to receive their proper due,
without distorting the verdict that voters render on the major-party
candidates. Approval voting should also reduce negative campaigning,
encouraging candidates to make more positive appeals to gain support from
voters with primary commitments to other candidates. Unlike the Borda and
Hare systems, approval voting can be implemented on existing voting
machines and is relatively easy for voters to understand.

Is the prospect of approval voting just an academic pipe? Not really. It
has already been used by professional science and engineering societies
totaling over 600,000 members and to elect a secretary-general of the
United Nations. It is now being considered by the Task Force on Election
Administration of the U.S. National Commission on Electoral Reform.
Perhaps best of all, it could be adopted in the United States without any
constitutional amendment; any state legislature could enact the enabling
statute. Isn't there a state that would like to make itself the pioneer
in electoral reform?

More information about the Election-Methods mailing list