Alternatives to RCV?

Should we consider other voting methods before supporting RCV?

Approval Voting
Voters choose as many candidates as they like. No preference is given to their choices. The candidate with the most votes wins. This method has the advantage that it’s easier to count the votes, and the ballots are simpler. The disadvantage is that it tends to choose a candidate who, in an RCV election, would have gotten relatively few 1st choice votes compared to 2nd and 3rd choice votes. Approval voting favors the candidate few love and fewer hate. The biggest disadvantage to approval voting is that voters are discouraged from voting for their 2nd and 3rd choices if they have significant preference for their 1st choice. It does not solve the “spoiler” problem. With RCV there is no risk to voting one’s 1st choice. Approval Voting is not currently used in any major political election in the USA.

Range
Voters assign a score (such a 0 – 10) to each candidate, with the candidate with the highest average score being elected. The disadvantage of this method is that some voters may be “tough graders” and other voters may be “easy graders” and their votes will not count equally. Range Voting is not currently used in any major political election in the USA.

Condorcet method
Voters ranked the candidates in order of preference. A pair-wise comparison of each candidate with each other candidate is done in the counting processes. The candidate who wins most often in these one-on-one contests is the overall winner. The disadvantage to this method is that it’s complicated and tends to favor the candidate who seems least offensive or not very well known. The Condorecet could elect a candidate who has very few 1st choices votes. Condorcet Voting is not currently used in any major political election in the USA.

Borda Count
Voters rank all candidates in order of preference. Based on this order, the candidates are assigned a score, with the first choice receiving the most points, the second choice receiving a smaller number, etc. with the last candidate receiving no points. The disadvantage to this method is that it does not solve the spoiler problem. Because the biggest loser is not eliminated first as in the RCV method, the high score you give your 2nd choice could lower the chance that your 1st choice could win; this disincentivizes voters from ranking several candidates. Borda Count Voting is not currently used in any major political election in the USA.

Are RCV elections problematic because they are “non-monotonic”?
An RCV election is “non-monotonic” when a candidate “gets more votes but this makes that candidate lose” if, and only if, this also causes that candidate to get relatively fewer 2nd choice votes. This is illustrated by scenarios below which compare the outcomes of two different elections. Usually such examples of non-monotonicity use X, Y and Z instead of letters associated with actual parties. This obscures the fact that not all ranking sequences are equally likely. For example, the majority of G voters are not likely to choose R as 2nd choice. The majority of R voters are not likely to switch to D or vice versa. If you substitute any combination of letters in this example (such as L instead of G or adding L as a fourth candidate), unlikely rankings will occur. This illustration shows that a paradox only seems to emerge in the second election when two D voters switched their votes to R, resulting in R losing.

Election 1
# of voters      their ranking
6         R > D > G
6         D > G > R
5         G > R > D
R wins

Election 2
# of voters      their ranking
8 [+2]        R > D > G
4 [-2]         D > G > R
5                G > R > D
G wins

This is not a paradox if you consider that, in the second scenario, although R got more 1st place votes, R did not get a sufficient number of the 2nd place votes of the loser. Here is the RCV way of looking at the outcomes:

Election 1
1st Round     2nd Round
RRRRRR      RRRRR
DDDDDD
GGGGG      eliminated
R wins

Election 2
1st Round     2nd Round
RRRRRRRR
DDDD      eliminated
GGGGG      GGGG
G wins

RCV is not designed to ensure that the candidate with the most 1st place votes wins. That is what our current “first-past-the-post” or “plurality” voting method ensures. RCV ensures that those who vote for underdog candidates get a chance to make their voices heard. The purpose of RCV is to get as many people as possible to voice their preferences and to elect candidates who appeal to at least 51% of voters.