[EM] Re: British Election and Duverger's Law

Araucaria Araucana araucaria.araucana at gmail.com
Fri May 6 10:09:49 PDT 2005

On  6 May 2005 at 00:52 UTC-0700, Alex Small wrote:
> Long time no post.  I'm wrapping up the writing on my dissertation,
> but I couldn't resist jumping in to post on the British election.
> The Liberal Democrats are putting in their strongest showing since
> the 1920's.  What's interesting from the non-partisan standpoint of
> this list is that Britain uses plurality voting from single-member
> districts, and yet the LibDems got 22% of the popular vote at last
> count and approximately 9% of the seats.  The usual rule of thumb is
> that plurality voting from single-member districts encourages the
> formation of a 2-party system.  That's certainly the case in the US,
> both nationally and in the 50 states (which can be seen as 50
> different units to compare).
> The appeal of the LibDems is even more surprising when you consider
> that it's a parliamentary system.  The stakes in a legislative race
> are even higher, so at first glance I would think that there's even
> more of an incentive to vote for one of the 2 major parties.
> Finally, while most of the other parties in the British Parliament
> are regional/ethnic parties representing Wales, Northern Ireland,
> and Scotland, the LibDems are more about issues and ideology rather
> than ethnic/regional identity.
> Now, it may be tempting to explain these results solely in terms of
> current events: Tony Blair has alienated elements of the left and
> center, and the Tories are such an abysmal mess that even Gray Davis
> has lost respect for them.  But the LibDems have persisted despite
> the fact that they've been the third party in size for 80+ years.
> I'm more surprised by their persistence over time than I am by their
> current popularity.
> Does anybody know why Duverger's Law has been so stubbornly resisted
> in Britain for 80+ years?  I'd be genuinely curious to know.
> Alex

Duverger's "Law" is not absolute, and I think it assumes some party
stability and regional homogeneity.  Extracting from the top of the
wikipedia entry (which ought to be imported into electowiki):

,----[ http://en.wikipedia.org/wiki/Duverger%27s_law ]
| Duverger's Law is a principle which asserts that a
| first-past-the-post election system naturally leads to a two-party
| system. The discovery of this principle is attributed to Maurice
| Duverger, a French sociologist who observed the effect and recorded
| it in several papers published in the 1950s and 1960s. In the course
| of further research, other political scientists began calling the
| effect a ülawý.
| While there are indeed many FPTP systems with two parties, there are
| significant counterexamples: Scotland has had until recently
| first-past-the-post and similar systems but has seen the development
| of several significant competing political parties. Many
| commentators regard the United Kingdom's Liberal Democrat party,
| since the 2005 General Election, as forming a 'third party' and
| creating a three-party system. Canada and India have multiple
| regional parties. Duverger himself did not regard his principle as
| absolute: instead he suggested that first-past-the-post would act to
| delay the emergence of a new political force, and would accelerate
| the elimination of a weakening force - proportional representation
| would have the opposite effect.
| Additionally, William H. Riker noted that strong regional parties
| can distort matters, leading to more than two parties nationwide,
| even if there are only two parties competitive in any single
| district. He pointed to Canada's regional politics, as well as the
| U.S. presidential election of 1860, as examples of often temporary
| regional instability that occurs from time-to-time in otherwise
| stable two-party systems (Riker, 1982).

In the US 1860 election, there was not only regional instability, but
the Whigs were disintegrating and the Democratic and fledgling
Republican parties (and others) were scrambling for dominance in a
highly charged race.

This entry appears to be very recently updated, BTW.

araucaria dot araucana at gmail dot com

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