Pros
- Highly proportionate - seats in parliament broadly match how many votes each party receives
- With a lower barrier to entry, new parties can start and be successful if established parties do not understand new social issues
- Voters get to choose which MP they want to interact with, and can choose according to subject specialism, party affiliation etc
- Closed list system is simple to use - voters mark one X for their first-choice party
- Open list system gives higher level of voter choice - voters can choose between candidates of the same party
- Easy to count on a regional scale and relatively easy for voters to understand how votes convert to seats
- Number of members can vary between constituencies to better fit geographic or administrative boundaries
Cons
- Can encourage the formation of many small parties (many countries use legal thresholds, generally 4% or 5%, to stop parties with very low support winning seats)
- The larger the region is, the less strong is the constituency link (Israel and the Netherlands have a single national constituency)
- The smaller the region is, the weaker the proportionality is (Finland and Spain use existing provinces)
- Party lists are based on political parties, so independent candidates have to create a ‘party list’ of one. If they win more votes than they need to get elected these votes are wasted
- [Closed lists] The voter has no choice or influence over individual MPs elected and MPs may not be local - often a weaker constituency link
- [Open lists] Can result in a very long ballot paper which may confuse voters
- [Semi-open lists] Most voters take the easy option and tick the party box – as a result the party ordering of the list is very rarely overturned
- Allocating seats by the d’Hondt method somewhat favours the larger parties
- The smallest regions can only give seats to the top parties
- Different size constituencies can create inequalities in share thresholds needed to win (easier to win seats in large cities than sparsely populated rural areas)
