[EM] Criterions for party-list PR systems

Vidar Wahlberg canidae at exent.net
Fri Sep 4 04:11:09 PDT 2015

This list mainly discuss election systems where votes are cast for
single candidates, rather than for parties. When voting for single
candidates, the voting system criterions make sense, but to what degree
can those criterions be used for a party-list proportional
representation system?

As an example, how would the later-no-harm criterion manifest in a
typical preferential party-list proportional representation system?
Would the following be a fair translation of the criterion?
- The criterion is failed if adding a party with lower preference to the
  ballot may cause a higher preferences to end up with less

How about the monotonicity criterion?
- The criterion is failed if ranking a party lower on the ballot may
  cause that party end up with more representation?

Are there any criterions you know of or can think of that typically
would not apply to candidate based systems, but would apply to
party-list PR system?

I found few discussions and resources regarding this topic, even though
party-list PR systems are used in a fair amount of elections.

Vidar Wahlberg

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