Richard Gunther and Larry Diamond, "Species of Political Parties: A New Typology," Party Politics, 9 (March 2003), 167-199.

First Paragraph:
For nearly a century, political scientists have developed typologies and models of political parties in an effort to capture the essential features of the partisan organizations that were the objects of their analysis. The end result is that the literature today is rich with various categories of party types, some of which have acquired the status of 'classics' and have been used by scholars for decades (e.g. Duverger, 1954; Kirchheimer, 1966; Neumann, 1956). We believe, however, that the existing models of political parties do not adequately capture the full range of variation in party types found in the world today, and that the various typologies of parties, based on a wide variety of definitional criteria, have not been conducive to cumulative theorybuilding. This article, therefore, is an attempt to re-evaluate the prevailing typologies of political parties, retaining widely used concepts and terminology wherever possible, consolidating and clarifying party models in some cases, and defining new party types in others. This is for several reasons.

Figures and Tables:
Figure 1: Extent of organization

Last Paragraph:
Political parties have not emerged or evolved in a continuous, unilinear manner, and neither have they converged on a single model of party. Instead, we believe that changes in the organizational forms, electoral strategies, programmatic objectives and ideological orientations of parties are the products of multiple causal processes -- some of them related to broadet long-term processes of social or technological change, others involving the less predictable innovative behaviour of political and social elites. If this is true, then it would be a mistake to rely on an excessively restricted number of party types. This would lead scholars to attempt to cram new parties into inappropriate models, or to abort the theory-building process by concluding in frustration that existing theories and models simply do not fit with established party types. Accordingly, we believe that the typology presented here -- less parsimonious but more fully reflective of the real variation in party types around the world -- should facilitate the testing of numerous hypotheses about the origins, functions and evolutionary trajectories of political parties in widely varying social, political, technological and cultural contexts.