NAME 329
26.10 (1) In a congressional district somewhere in the U.S. West a
new representative is being elected. The voters all have one-dimensional
political views that can be neatly arrayed on a left-right spectrum. We
can define the “location” of a citizen’s political views in the following way.
The citizen with the most extreme left-wing views is said to be at point
0 and the citizen with the most extreme right-wing views is said to be at
point 1. If a citizen has views that are to the right of the views of the
fraction xof the state’s population, that citizen’s views are said to be
located at the point x. Candidates for office are forced to publically state
their own political position on the zero-one left-right scale. Voters always
vote for the candidate whose stated position is nearest to their own views.
(If there is a tie for nearest candidate, voters flip a coin to decide which
to vote for.)
(a) There are two candidates for the congressional seat. Suppose that
each candidate cares only about getting as many votes as possible. Is
there an equilibrium in which each candidate chooses the best position
given the position of the other candidate? If so, describe this equilibrium.
26.11 (2) In the congressional district described by the previous problem,
let us investigate what will happen if the two candidates do not care
about the number of votes that they get but only about the amount
of campaign contributions that they receive. Therefore each candidate
chooses his ideological location in such a way as to maximize the amount
of campaign contributions he receives, given the position of the other.*
Let us define a left-wing extremist as a voter whose political views
lie to the left of the leftmost candidate, a right-wing extremist as a voter
whose political views lie to the right of the rightmost candidate, and a
moderate voter as one whose political views lie between the positions
of the two candidates. Assume that each extremist voter contributes to
the candidate whose position is closest to his or her own views and that
moderate voters make no campaign contributions. The number of dol-
lars that an extremist voter contributes to his or her favorite candidate
is proportional to the distance between the two candidates. Specifically,
we assume that there is some constant Csuch that if the left-wing can-
didate is located at xand the right-wing candidate is located at y, then
total campaign contributions received by the left-wing candidate will be
$Cx(y−x) and total campaign contributions received by the right-wing
candidate will be $C(1 −y)(y−x).
* This assumption is a bit extreme. Candidates typically spend at least
some of their campaign contributions on advertising for votes, and this
advertising affects the voting outcomes.