--- john hull <[EMAIL PROTECTED]> wrote: > ... So then I thought, suppose a third party were > let into the race, does the MVT still hold w/ for 3 or > more candidates?
MVT posits a bell-shaped distribution of political views, and the parties respond to that. Think of hot-dog vendors at a beach. Two vendors will position themselves at the middle, each getting half the business. Comes a third vendor. If he is in the center, each now gets 1/3 the sales. If one vendor moves just a bit away, he gets 1/2 while the others get 1/4. So a second vendor too moves a bit the other way. The middle vendor, left with little share, now moves a bit further towards one end than one of the other 2. The equilibrium will be that they will spread themselves so that each gets 1/3 of the sales, 1/6 on either side. So, for politic parties, expect a left, right, and middle party. The equilibrium might be unstable sometimes as the left or right party goes to the middle to get a greater share, but if political positions are flexible, the middle party will then move to the other side of that party, and if they learn that moving around does not gain anything in the long run, the equilibrium will hold. In reality, a political party may not be able to change its doctrine so easily, so we can see unequal shares for a while, but over the long run, except for ideologically driven parties, they will move towards equal shares, or more likely, two of the parties will merge, and they will return to a 50/50 split at the middle. The reason for the merger is that two parties are more stable than three parties, since once in a while there will be an ideologically driven candidate (e.g. Goldwater) who will move towards one end and reduce the party's share. That can happen with two parties (again, Goldwater) but less often, since the middle position is less ideology-driven. Fred Foldvary Fred Foldvary ===== [EMAIL PROTECTED]
