Daily Archives: January 7, 2008

Our Voting System Is a Loser

An article featuring Range Voting is in the news. William Poundstone is interviewed by Mother Jones. This is also featured on Slashdot.

The basis for the coverage is Poundstone’s new book Gaming the Vote: Why Elections Aren’t Fair (and What We Can Do About It)

From the MotherJones interview:

It’s heartening to know, as primary season begins, that ours may be the worst of all the voting systems in common use. That’s the takeaway from Gaming the Vote: Why Elections Aren’t Fair (and What We Can Do About It), the latest of eleven books by William Poundstone, a professional skeptic who studied physics at the Massachusetts Institute of Technology before he began pumping out nonfiction in 1982.

Poundstone became interested in voting theory after reading about Arrow’s Impossibility Theorem, a 59-year-old paradox wherein economist Kenneth Arrow, now a professor emeritus at Stanford University, identified what he perceived as a fundamental flaw in our democracy: Put simply, he argued that devising a perfectly fair voting system is mathematically impossible.

Mother Jones: Is there a way around Arrow’s Impossibility Theorem?

William Poundstone: For decades, there was almost a kind of despair among voting theorists of getting any better system than we had. What’s interesting, though, is that the impossibility theorem doesn’t apply to systems where you score the candidates rather than rank them. With scoring, you’re essentially filling out a report card—if you think there are two candidates who deserve four stars you can give them both four stars—whereas with ranking you have to artificially give one a number one and one a number two. That turns out to be crucial.

MJ: And yet plurality voting—where a person can vote for only one candidate for a particular office—is the most common system in use. What’s wrong with it?

WP: Whenever you have two candidates whose support overlaps, that’s bad for both of those candidates, the obvious example being Nader and Gore in 2000. So a candidate can be a spoiler and cause the second most popular candidate to win. This is something that’s been appreciated at least going back to the 18th century, and people have tried to devise different ways of dealing with it, but for a very long time this was one of those unsolvable problems.

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