Defective Methods

[DEMOREP1 at aol.com]

All of the following methods have some major defects in choosing a majority
consensus winner for a single office.  

Plurality- Obviously a plurality winner might not be the choice of a majority.
Major insincere voting is probable for the first (i.e. only) choice.
Example 1992 U.S. President election
43  C
39  B
12  P > B
6    P > C
100
C won but B might have been a consensus majority winner.

Top 2 in Runoff- One of the losers might be a majority winner if head to head
votes were used.
Example
45 A > C
42 B > C
10 C
  3 D > C
100
C/A  55/45, C/B  58/42, C/D  97/3

Approval- does not rank choices. Counts more choices than needed to get a
majority.  Can cause a first choice majority to lose.
Example--
26   A > B > D
25   A > C > B
25   C > B > D
24   C > D > B

A 51, B 100, C 74, D 75
B wins using Approval, A has a majority of first choice votes.

Instant run-off - repeatedly drops candidate with lowest number of votes
A dropped loser might be a head to head (Condorcet) winner.
Example-
47  D > F
42  B > F
11  F
100

(regular) Bucklin- adds earliest choices until there is a majority
Major insincere voting is probable for second choice especially and later
choices to a lesser degree.
Example

35 G
25 H 
20 J > H
15 K > H
  5 M > G
100

H gets 60 adding the 1st and 2nd choices. The J, K and M voters may really
want to vote for each other as second choices.

Folks should add other defective methods.