Advantages of Single Non-Transferable Vote
- The most important difference between SNTV and the plurality/majority systems described earlier is that SNTV is better able to facilitate the representation of minority parties and independents. The larger the district magnitude (the number of seats in the constituency), the more proportional the system can become. In Jordan, SNTV has enabled a number of popular non-party pro-monarchist candidates to be elected, which is deemed to be an advantage within that embryonic party system.
- SNTV can encourage parties to become highly organized and instruct their voters to allocate their votes to candidates in a way which maximizes a party’s likely seat-winning potential. While SNTV gives voters a choice among a party’s list of candidates, it is also argued that the system fragments the party system less than pure PR systems do. Over 45 years of SNTV experience, Japan demonstrated quite a robust ‘one party dominant’ system.
- Independent candidates are easily accommodated.
- Finally, the system is praised for being easy to use and understand.
Disadvantages of Single Non-Transferable Vote
- Parties whose votes are widely dispersed will win fewer seats than otherwise, and larger parties can receive a substantial seat bonus which turns a plurality of the vote nationally into an absolute majority in the legislature. These anomalies may lead to significant protests against the results and the system. Although the proportionality of the system can be increased by increasing the number of seats to be filled within the multi-member districts, this weakens the voter–MP relationship which is so prized by those who advocate defined geographical districts.
- As with any system where multiple candidates of the same party are competing for one vote, internal party fragmentation and discord may be accentuated. This can serve to promote clientelistic politics where politicians offer electoral bribes to groups of defined voters.
- Parties need to consider complex strategic questions of both nominations and vote management; putting up too many candidates can be as unproductive as putting up too few, and the need for a party to discipline its voters into spreading their votes equally across all a party’s candidates is paramount.
- As SNTV gives voters only one vote, the system contains few incentives for political parties to appeal to a broad spectrum of voters in an accommodatory manner. As long as they have a reasonable core vote, they can win seats without needing to appeal to ‘outsiders’. However, they could win more seats by wooing voters from other parties by putting up candidates acceptable to them.
- SNTV usually gives rise to many wasted votes, especially if nomination requirements are inclusive, enabling many candidates to put themselves forward.