Friday, 19 July 2013

Back to the Basics: The Game of Elections

The election is a game for the politicians. It is a competition for them which they have to win. But lets not get mistaken, it is a game for us too: We have to use our one vote to ensure the best possible outcome according to our perspective. This responsibility does not end at choosing who you want the winner to be and voting for him, but requires you to generate a ranking of the candidates in order of preference and calculate who your vote should go to backwards.

Those familiar with economics will recognize my attempt at explaining the basics of Game Theory. But to understand the need for this we must first understand how elections take place in India and what are the implications.

I am sure all of us are aware of the absolute basics: The country is divided into 543 constituencies which are suppose to be roughly equal in terms of their population. Each of these constituencies elects a representative. This representative need not even achieve a simple majority (i.e. 50%); as long as he has more votes than any other single candidate he will be given the seat in the Parliament. For example, if there are 3 people running from a constituency and the vote share is divided in the ratio 25%, 35% and 40%, the candidate with 40% will be declared the winner. This is called First-past-the-post voting (FPTP).

What does such a mechanism imply? It can result in skewed representation. For example in the 2012 UP state elections SP (Samajwadi Party) received 29.3% of vote share and were allocated 226 seats in the assembly out of 403, where as BSP (Bahujan Samay Party), who received 25.9% of the vote share were allocated only 80 seats. This happened because the SP won several seats against the BSP over a very small margin. Thus while BSP received considerable votes overall, they were thwarted in individual battles and thus annihilated in the war in the world of FPTP.

This may seem like an unfair mechanism, specially when compared to the proportional representation method. But that is a debate for another blog post. What I would like to discuss is what the voter should do.

Let us imagine that the people who voted for BJP would rather have BSP if their only other option was SP. Their strategy should be obvious: Instead of voting for BJP, who anyway did not have a chance of coming to power, they should have voted for their next best choice which was BSP. If we assume that in each constituencies the vote share was identical to the state level data, then with the transfer of BJPs 15% to BSP, the party would be propelled to number one status with almost 41% of the vote share. Thus the BJP supporters might not get their first choice, but at least they would not be stuck with their 3rd or 4th one.

This example is obviously simplified using several assumptions, but the principle remains the same. At the central election level this effect can be observed with Modi being portrayed as the PM candidate for BJP. While Congress' abysmal performance has lost them support, voters who fear Modi more will fall back to Congress which is the only credible force to stop BJP. The same applies to people who fear another five-year reign of Congress: Recognizing this possibility they will leave their regional parties and flock to Modi (also discussed in Back to the Basics: Polarising Mr Modi).

The FPTP system often has the effect of bringing the war down to two parties. Understanding the system is important or your vote may actually count for nothing.

2 comments:

  1. Tactical voting is a double edged sword though. By very virtue of doing so you are in fact perpetuating the two-party system. And while yes it may be tactically smarter in the way you suggest, it is still theoretically dishonest no?

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    1. That really depends on the objective you have set for voting. Is the objective just to reveal your favorite or is the objective to ensure you achieve the best possible outcome for yourself?

      Suppose there are 3 parties - A & B which are larger than a 3rd part C. If you prefer C the most and are indifferent between A & B then you would and should continue to vote for C. But if you are not indifferent, then you should vote for the one that you prefer more. Anything else would be irrational.

      People at an individual level cannot determine whether it will be a multi-party or two-party system, it is the system that forms the incentives and individuals just play the game. The way to fight the two-party system would be the mechanism of proportional representation (instead of FPTP) not expecting irrational but 'honest' behavior from the electorate.

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