[EM] (no subject)

[Bob Richard (lists)]

The expert on the question of what determines the number of political 
parties is the political scientist Matthew Shugart (  
http://fruitsandvotes.wordpress.com ). According to him, the single best 
predictor is district magnitude, rather than the specific form of 
proportional representation. Since STV is usually used with fewer seats 
per district than list PR, it might well be associated (statistically at 
least) with fewer parties. But I doubt that there is any significant 
difference between MMP and party list.

I'll have to look through Shugart's books to determine whether he has 
tried to quantify differences among list PR, MMP and STV. I know that he 
has the data set for this analysis.

--Bob Richard

------ Original Message ------
From: "Kristofer Munsterhjelm" <km_elmet at t-online.de>
To: "Rob Lanphier" <robla at robla.net>; 
election-methods at lists.electorama.com
Sent: 11/29/2020 9:52:26 AM
Subject: Re: [EM] (no subject)

>On 28/11/2020 14.11, Rob Lanphier wrote:
>>  Hi everyone,
>>
>>  Here's a very interesting question over on the /r/EndFPTP subreddit:
>>
>>  <https://www.reddit.com/r/EndFPTP/comments/k27f5c/what_do_countries_with_3rd_party_viability_have/>
>>
>>  Here's what /u/9d47cf1f had to ask:
>>
>>>  What do countries with 3rd party viability have in common?
>>>
>>>  I suspect that MMP is a better predictor for 3rd party viability than other
>>>  factors and I’m looking for a list of modern democracies by voting method &
>>>  3rd party viability to test that hypothesis but I’m finding that to be a
>>>  frustratingly difficult Google search. Does anyone know where such a list
>>>  could be found?
>>
>>  The question from "9d47cf1f" made it clear that those of us that have
>>  wiki skills need to fix up these two articles:
>>
>>  * <https://en.wikipedia.org/wiki/MMP>
>>  * <https://electowiki.org/wiki/MMP>
>
>What he's saying seems wrong. There are lots of continental European
>countries that use party list (not MMP) and have many parties. There
>were also lots of parties in STV-era New York.
>
>So I'm not sure how MMP could be a better predictor than, say, going
>from single-member district Plurality to party list.
>----
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