Talk:Median voter theory

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[edit] Confusing image

I think the image is confusing. What does y-axis mean (what kind of value)? Must point M exactly coincide with the peak? Is it important that the graph is so symmetrical?
What does "already won" mean? (I think some "gray" voters will vote for A or B too) --Y2y 11:12, 12 March 2007 (UTC) Y2y 11:59, 12 March 2007 (UTC)

The main issue with the image is that there are no "hard" values for the graph. The 'M' stands for median and by its very nature must be at the peak of the curve, which by its very nature must be symmetrical. The Y-axis is somewhat arbitrary and the X-axis represents increments of people, and goes from 0% to 50% towards the M.
"Already won" signifies the voters who have made up their minds, or decided to vote for a certain candidate who endorsed their opinion on the issue. The idea is that there are some people who will be extremists and others who are more middle of the road - say the issue at hand is the eradication of all apple trees. Some people will right away be for it (those maybe allergic to apples?) while others will right away be against it. Those are the starting points, the edges of the skirt of the graph. Others might need more convincing to make a decision. In such an idealized representation, one would think that the people with the most extreme views are very small in number, and that most people are indifferent or wavering on the topic. In this schematic Party A only has to approach the median - or water down their policy on the matter - to a much smaller degree than Party B.
Sorry, I can't get into too many details about the exactness of this type of graph, but hopefully this explanation will allow you to see it in a different light and reflect on its data. JesseRafe 02:01, 7 April 2007 (UTC)

I think this image is very useful. It explained the basic thrust of the article to me in a single glance! It might benefit from a couple of more labels for people unaccustomed to interpreting such a graph, but overall it was very helpful to me as a reader. I must take issue with Jesse's comment above, though. The median is not the center of the X axis, it's the position along the X axis where the size of the left and right slices cover an equal area. Also, not all opinion graphs need be bell-shaped. A highly polarized opinion graph would have two humps, and it's easy to think of an example that would have many humps.

Here are some suggested changes to the graph:

  • Strike the arrow at the right of the X axis. There is nothing further to the right than 100% support for choice B. (or add an arrow to the left)
  • Drop the entire Y axis line.
  • Spell out the L, M, and R labels. Try adding the words 'left' and 'right' floating in the whitespace above the curve. The median might be represented by a pale vertical line and the word median above it.
  • Consider making the curve asymetric. This will allow the median to be distinguished from the mean, by having the median also positioned asymetrically. Maybe the hump could be shifted left, and the red area shrunk a bit. Then the median line could be visibly off center. On the other hand, such a change may introduce additional confusion for some readers by adding another avenue for misinterpretation.
  • Change the caption to something like this: "A conceptual graph of a one-dimensional policy space, with potential voters represented as two-dimensional space bonded by a curve. Candidates A and B currently have the support of a shaded area, and attempt to attract more uncommitted voters by migrating their posotions toward the moderate center.

By making the graph look a bit less graph-like, you clue the reader that it's not meant to be properly quantitative, but conceptual. Anyway, I like the graph, even in its current form. I'm sure it can be adjusted or just left as-is. --Loqi T. 03:32, 15 May 2007 (UTC)

What about this: make a series of 3 graphs, with the first as an initial condition (neither at the median), the second like the first but with the formerly losing candidate moving to the median and winning, and the third at equilibrium.
CRGreathouse (t | c) 20:24, 3 July 2007 (UTC)

[edit] Normal Distribution

I don't think it is necessary that the graph forms a normal distribution. Claiming the /median/ voter would always give a majority, regardless of the shape of the curve, no?

Exactly. What if the issue is "how tough should the law be against pedophilic murder"? The median voter would probably be far away from the median possible position (say, giving only a few years prison, or 50% of all people arrested for pedophilic murder automatically go free). Sagittarian Milky Way 00:06, 21 September 2007 (UTC)

[edit] Is this a good way to write a sentence?

This article now begins as follows:

The median voter theory, also known as the median voter theorem and the median voter model, is a famous voting model positing that in a majority election, if voter policy preferences can be represented as a points along a single dimension, if all voters vote deterministically for the politician that commits to a policy position closest to their own preference, and if there are only two politicians, then if the politicians want to maximize their number of votes they should both commit to the policy position preferred by the median voter.

So it says "if blah blah, if blah blah blah, and if blah blah, then if blah blah, ...." Michael Hardy (talk) 02:53, 17 April 2008 (UTC)