The Effective Number of Parties

@article{Golosov2010TheEN,
  title={The Effective Number of Parties},
  author={Grigorii V. Golosov},
  journal={Party Politics},
  year={2010},
  volume={16},
  pages={171 - 192}
}
The Laakso—Taagepera index of the effective number of parties, while satisfying most of the requirements of this aggregate quantity, tends to produce unrealistically high scores for party constellations in which the shares of the largest parties exceed 50 percent, and can produce misleading results in several other situations. After reviewing the structural properties of the Laakso—Taagepera index and supplements or alternatives to it proposed in the literature, this article proposes a new… 

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