Why first-past-the-post voting is fundamentally flawed (US perspective)

Why first-past-the-post voting is fundamentally flawed
12 April 2008
From New Scientist Print Edition.
Phil McKenna

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One person one vote is the mantra of democracy. And as Americans prepare to elect a new president this year, they'll be weighing up who to cast their precious vote for. Yet giving each citizen just one vote may not serve democracy's best interests. It can all too easily throw up a winner who in a straight fight with the runner-up would not be the majority's choice - surely a negation of democracy.

How can this happen? It's to do with the way voters are allowed to express their preferences, and how those choices are turned into a winner. Most elections in the US, the UK, Canada, India and many other countries use what is technically called a plurality voting system (better known as first-past-the-post) for single-winner elections. Every voter chooses one candidate from those standing, and the candidate with the most votes wins.

It's beautifully simple. But it can also be strongly influenced by fringe candidates with relatively little support. By taking votes that would otherwise go to one of the leading candidates, these "spoilers" can tip the outcome in favour of that candidate's main rival. In five of the last 45 US presidential elections, plurality voting has handed the White House to the second most popular candidate, according to William Poundstone, author of Gaming the Vote: Why elections aren't fair. "It's really the worst system. Its only virtue is that it is the simplest way of voting, which is why we put up with it," he says.

Voting reform initiatives in the US usually focus on problems with voting machines and on the electoral college used in a presidential election - an antiquated system that gives more weight to voters from some states than from others. Yet arguably the larger problem with elections in America and elsewhere is plurality voting itself. Is there a fairer alternative?

Researchers and politicians have long known of plurality's weaknesses, but until recently most believed the alternatives weren't any better. In 1950, economist Kenneth Arrow, then a PhD student at Columbia University in New York, seemed to prove once and for all that it was impossible to have a method of voting that was entirely fair (Journal of Political Economy, vol 58, p 328).

via science.org.au

To read article;

http://www.science.org.au/nova/newscientist/049ns_001.htm

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