Monday, September 19, 2011

Voting Methods

It turns out that there is no perfect voting method. This is mathematically shown with Arrow's Impossibility Theorem. I won't thoroughly describe it, but the gist is that if you want a voting system to have certain properties, they can't all be satisfied.

There are many different voting systems, each with their ups and downs. Here are some of them.

Popular Vote:
Everybody picks one candidate and the candidate with the most votes wins. This is the only type of vote we see in America. The problem with it is that it only works perfectly in a two option vote.  I think that because this system works best in two-option systems, it forces us towards a two-party system. In multi-option votes, you often run into the situation where people don't vote for who they really want, but instead for the 'potential winner' who most accurately represents their views.

Approval Voting: 
Each person gets to vote for as many candidates, and the one with the most votes wins. This is type of voting allows people to vote for their preferred candidate without 'wasting' their vote on a loser. There are complaints that this system tends to elect the least hated as opposed to the most liked, if you will, since voters cannot weigh their votes differently.

Point-Based Systems:
Voters are given a number of points to distribute among the candidates; the candidate with the most points wins. This system has the problem that a person cannot support multiple candidates without giving up support for their favored candidate.

Ranked Voting:
There are many versions of this system, the most basic of which asks the voters to rank the candidates and order and each ranking bestows a number of points. The candidate with the most points is the winner. The problem with this most basic version is that you have to decide how many points a certain ranking is worth, and it's a somewhat complicated system that can force people to make hard decisions about their exact rankings.

Single-Transferable Vote:
This is a system that Australia uses. Each person ranks any number of candidates to their liking. The vote goes to the number 1 ranked candidate on each ballot initially. Then, any ballot where the number 1 ranked candidate is a sure loser is reassigned to that ballot's number two candidate. Losing parties are eliminated and their ballots redistributed again until a winner is clear.

There are two important factors when it comes to voting systems. How they work needs to be clear to the votes. They also need to accurately represent the desires of the voters. Striking this balance is difficult, especially since there is no perfect voting method. Soon, I'll talk about the ways that I would change our American electoral system.