Blog 7: Duverger's Law

An interesting trend in politics is that the effective number of parties in a country has far more to do with the electoral rules of the government than the actual support for party platforms. Duverger’s Law asserts that a Single Member District Plurality (SMDP) tends to produce a two-party system, whereas Proportional Representation (PR) tends to create multipartism. Duverger’s Law is supported by the hybrid system of modern day Germany that allocates legislative seats proportionally.

By calculating the effective number of parties in Germany, we find that the country has a multiparty system. In the 2005 Parliamentary Election for the Bundestag (the lower house of the German Legislature), the Social Democratic Party achieved a plurality of the vote with 34.2% for which they were rewarded 222 seats. The total number of seats acquired, the number earned from winning a plurality with their constituency, and the percentage of votes each party received can be seen in the following table:

Political Group		Total	Constituencies	Vote Percentage	P2
Social Democratic Party		222	145	34.2%	.117
Christian Democratic Union		180	106	27.8%	.077
Free Democratic Party		61	0	9.8%	.010
Left Party		54	3	8.7%	.008
Green Party		51	1	8.1%	.007
Christian Social Union of Bavaria		46	44	7.4%	.006

   (Election information gathered from Inter-Parliamentary Union)

By dividing 1 by the sum of the squared percentages, we can conclude that Germany has 4.48 effective parties. This is a result of their hybrid electoral system, which aims to achieve the benefits of both SMDP and PR systems. Of the 598 seats in the Bundestag, 299 are directly elected by their constituencies through a plurality system. However, every citizen has two votes. So after casting their first vote for a specific politician to represent their district, they also select a party from a list. If a party passes the 5% threshold (CIA World Factbook) and is not adequately represented by the winners of the direct elections, they will be rewarded seats until their representation is proportional to the amount of votes they received. (Bunderstag Official Site)

The benefits of this system for smaller parties are clear. Notice that the Free Democratic Party received nearly 10% of the vote, but did not achieve a plurality in any constituency. If Germany exclusively used a SMDP system (like the United States), they would not have received any seats in the legislature despite three less popular parties having at least some representation. But because of the proportional allocation based on party lists, they received 61 seats. Because citizens do not have to worry about whether their favorite party actually has a chance of winning, they do not have to make any concessions for the “lesser of two evils.” Smaller parties like the Free Democratic Party, Left Party, and the Green Party all receive the number of seats they deserve based on public opinion.

Conversely, parties who win a disproportionate number of elections will not receive as much help from the PR component of the German system. This is generally of the greatest disservice to the largest parties like the Social Democratic Party and the Christian Democratic Union, though this is not always the case. For example, the Christian Social Union of Bavaria managed to win 44 constituencies in 2005, despite only receiving 7.4% support overall. So they gained only two extra seats, to bring their total to 46.

Because the innovative German hybrid system provides many of the perks of both SMDP and PR systems, it has influenced the electoral systems of other nations. Citizens are able to directly elect a particular individual to specifically represent them, and small parties are adequately represented. The presence of a multiparty system in Germany supports Maurice Duverger’s theory that proportional representation allows for the existence of multiple effective parties.

References

CIA World Factbook – Germany Government https://www.cia.gov/library/publications//the-world-factbook/geos/gm.html

            German Bunderstag – How votes are translated into seats http://www.bundestag.de/htdocs_e/bundestag/elections/arithmetic/index.html

            Inter-Parlimentary Union – Deutscher Bundestag (Federal Diet)

http://www.ipu.org/parline-e/reports/arc/2121_05.htm