<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:13px"><div>I've just had a brief look, but I have a couple of questions/points.</div><div><br></div><div>From: Vidar Wahlberg <canidae@exent.net><br>To: election-methods@lists.electorama.com <br>Sent: Friday, 31 October 2014, 21:52<br>Subject: [EM] Preferential Party-List Proportional Representation (PPLPR)<br> </div><div>>Example 1, three parties, L and R voters with C as 2nd preference:<br>> Votes:<br>> 40 L>C<br>> 20 C<br>> 40 R>C</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div>> Step 1:<br>> Count up support for each party using only the first preference.
This<br>> result will serve as a base for the next step:<br>> L: 40%<br>> C: 20%<br>> R: 40%</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div>> Step 2a:<br>> Iterate through all unique combination of 1st preference on votes<br>> (horizontal header of matrix), and move voter support to the 2nd<br>> preference on the votes. This will create a matrix:<br>> | L | C | R - "Excluded" 1st preference<br>> ----+-------+-------+-------<br>> L | - | 40+ 0 | 40+ 0 - L is not 2nd pref. on any C or R votes<br>> C | 40+20 | - | 40+20 - C is 2nd pref. on both L and R votes<br>> R | 40+ 0 | 40+ 0 |
- - R is not 2nd pref. on any C or R votes<br>> Sum | 100 | 80 | 100</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div>> Do note that the value before the plus sign is the result from Step 1,<br>> while the value after is from the 2nd preference on the votes.</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;">Should the C row be 20+40 rather than 40+20 or am I not understanding what
that table is?</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;">>Example 2, four parties, one very large, three small:<br>> This is an exaggerated example, mostly to demonstrate that large<br>> parties can't "vote away" opposition.<br>> Votes:<br>> 90 A>B<br>> 0 B<br>> 10 C>D<br>> 0
D</div><div> </div><div>[snip]</div><div><br></div><div>> Step 2c:<br>> A: 87%<br>> B: 3%<br>> C: 7%<br>> D: 3%</div><div>> A voters could not move more than 3pp away from C (and C voters could<br>> not move more than 3pp from A). If C voters had not ranked D as 2nd<br>> preference then the result would be A: 90%, B: 3%, C: 7%, D: 0%. Do<br>> however note that if D was excluded from the election, A voters would<br>> be able to move more support from C to B (I'll come back to this<br>> "feature" later).</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px;
font-style: normal; background-color: transparent;">So is step 2c the result? Just to clarify, if 10% of voters vote C and with no second preference, then C would only get 7% of the seats in an ideal situation (no seat rounding)? Is that a good thing? Also, if A is strictly preferred to B and C to D, does it make sense to award B and D any seats?</div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;"><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px; font-style: normal; background-color: transparent;">Also, presumably already-existing STV methods could be used for preferential party list anyway. For example, if there are five seats and three parties (A, B and C), then if someone's preference was
A>B>C, then this would be translated into A1...A5>B1...B5>C1...C5. What are the advantages of your method over using STV in this way?<br></div><div><br></div></div></body></html>