Saturday, 2 November 2013

Tea party and UKIP: What happened to the median voter theorem?

The median voter theorem is a workhorse of public choice and helps make sense of political manoeuvrings. Informally, the theorem says that if preferences are single peaked then the median voter will be on the winnings side of any majority vote. To say that preferences are single peaked essentially means that the vote is on a 'one dimensional issue' whereby that the closer is the outcome to a person's ideal then the happier they are. This naturally lends itself to talking of left wing, right wing and the centre ground. The median voter is then the person in the middle. And that is why the median voter will always be on the winning side: If the median voter prefers the 'left wing' option then the median voter and everyone to the left will vote for that option and it has a majority. Similarly, If the median voter prefers the 'right wing' option then the median voter and everyone to the right will vote for that option and it has a majority.
      If the median voter will always be on the winning side then political parties are naturally going to compete for the median voter. The median voter theorem is, therefore, very useful in making sense of the two party system that we have in countries like the US and UK. It tells us why the median voter is where the real action is always going to be: this is the vote politicians are competing for. And it also helps us understand why the 'centre ground' shifts over time as the preferences of the median voter evolve.
       Recent events, however, seem to cast doubt on the application of the median voter theorem. In the US we have the unyielding influence of the Tea Party wing of the Republican party. In the UK we have the emergence of the UK Independence Party as a political force. In both cases there is a clear pull towards the right wing: this is a battle far from the centre ground where we would expect to find the median voter. So what is going in? Interestingly, I think we can trace two slightly different explanations for this lurch to the right in the US compared to the UK.
        Looking to the US first: I see the Tea Party as essentially an attempt to move the centre ground to the right. The preferences of voters are clearly not fixed in stone and so an attempt to move the centre ground is not a completely dumb thing to do (if you are at the extremes of the political spectrum). But, it is political suicide from the perspective of the Republican Party because it leaves the centre ground wide open for the Democrats. And, herein lies the big flaw in the Tea Party's approach: the party in power has a lot more leverage to put their view across and move the centre ground. So, the Republicans are probably going to lose on both counts - no power and no shift to the right in the centre ground. The deal that concluded the recent government shutdown seems to illustrate the point nicely. The median voter theorem, therefore, is fine - it is just some in the Republican Party could do with being told about it!
       What about the UK. Here, I do not see much attempt to move the centre ground. Instead I just see general disillusionment in politics. The median voter theorem offers a good explanation for this. Basically, while political parties fight over the median voter everyone else can feel a little disenfranchised. Those to the more extreme right and left will feel most frustrated that 'no one gives them what they want'. This leaves the way open for protest votes such as those currently going to UKIP. I say protest vote on the basis that UKIP has no realistic chance of getting power. Note, however, that if a chunk of the electorate from the right wing of the political spectrum is going to vote for a party with no chance of winning then the 'electoral' centre ground moves to the left. Voters of UKIP, thus, face trading off a vote for something they believe in for an outcome even more removed from what they want. Come election day I have a feeling the UK public will ditch UKIP and the median voter theorem will prove its worth again. But, only time will tell.

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