Additional Member System (AMS)
The Additional Member System (AMS) is a hybrid voting system used to elect Members of the Scottish Parliament (MSPs). It aims to reduce the gap between the percentage of seats and the percentage of votes a party receives, making it more proportional than FPTP.
Definition: AMS is a mixed electoral system that combines elements of First Past the Post with proportional representation.
Under AMS, voters have two votes:
- A constituency vote to elect MSPs for specific constituencies (similar to FPTP)
- A regional vote to elect regional MSPs, with 7 MSPs elected from each of the 8 regions
The regional vote results are calculated using the d'Hondt formula, which helps balance out the disproportionality that might occur in the constituency vote.
Example: In the 2016 Scottish Parliament election, the SNP won 59 constituency seats but only 4 regional seats, demonstrating how the system compensates for strong performance in one area.
AMS increases proportionality and rewards parties more fairly for the votes they receive. For instance, in the 2016 Scottish Parliament election, the Green Party received 4.7% of seats with 6.6% of the vote. This is more proportional compared to the 2015 UK general election under FPTP, where the SNP won 95% of Scottish seats at Westminster with only 50% of the vote.
Highlight: AMS provides voters with more choice, as it increases the number of parties and candidates standing in the second ballot.
In the 2016 Scottish Parliament election, there were 23 parties on the second ballot in Glasgow and the Lothians, giving voters a wider range of options. This system also allows voters to potentially have access to 8 MSPs, increasing their chances of finding a representative who shares their views.
However, AMS is not without its criticisms. Voters have no say in the order a party ranks its list MPs, and parties are not required to register their candidates on the ballot paper. This lack of transparency can lead to situations where voters may end up with an unknown representative as their MSP.



