Democracy, Voting and The General Will: The concept of the Median Voter Theorem
Everyone has their own preferences when it comes to how they want their country to be governed. It is no surprise that no two people will have the exact same ideals and interests, so how do we end up with so many people identifying themselves with the same political party, such as being a “Democrat” or a “Republican”?
The answer is intuitive: these people choose the political parties that most fit their ideals. Suppose in an overly simplified version of politics, that the government in charge would have to decide how much tax they want to impose on a certain good, say cigarettes. In the hypothetical situation where there are only 5 distinct options, $0, $20, $40, $60 and $80, let’s say that the population’s opinions are as described by the graph below:
So apart from the normal spread of random opinions for whatever personal reasons the population has, there would be the hardcore smokers who would advocate no tax and the hardcore anti-smoking campaigners who would advocate the largest amount of tax they can find. The majority resides on two extremes, so what happens?
According to the Median Voter Theorem, the median (or halfway point basically) will be chosen. In this case this would be a $40 tax. This is not because the most people would agree with that number, but because people will be the least upset. If we took the tax to be at its maximum at $80, then we would have uproar from the smokers, and if we had no tax, then those against smoking with a conviction would also be visibly upset. By choosing the midpoint, then less of the population would be prone to disagreeing strongly with the new policy.
In reality, it’s much more complicated than this. When people adhere to a political party, they seldom do it for a difference of only 20 dollars on a sales tax on a product they may not even consume. But the concept of upsetting the least people and being close to the midpoint and hence a “non-radical” political party still stands, as they appeal to the largest number of people. The tempering down of the more extreme and less popular ideals leads to the will of all being trimmed by our democratic system, into the general will.
For a more technical, definitive and mathematical approach to this, check this out: http://en.wikipedia.org/wiki/Median_voter_theorem