Mixed electoral systems: a conceptual and empirical survey

Abstract

Until recently, mixed electoral systems have attracted minimal academic attention. Recent developments warrant reconsideration. At present no less than 29 countries, totalling about one-fifth of the world's population, use mixed systems for elections to their first or single chamber. However, there is no consensus in the literature as to whether mixed electoral systems are in a category of their own. Numerous scholars use the concept but do not agree on what it means exactly. We propose a rigorous definition of mixed systems, and argue that electoral systems should not be classified as mixed for the sole reason that they produce results in between those resulting from plurality or majority and PR. Rather, the crucial feature of a mixed system is that its mechanics involves both PR and plurality or majority. We distinguish between independent and dependent combinations, the latter corresponding to those cases where the application of one formula depends on the outcome produced by the other formula. We identify five basic types of hybrids: superposition (now exemplified by Japan), correction (Germany), coexistence (French Senate), fusion (French municipal elections) and conditional (the 1923 and 1953 Italian election laws). Existing and older systems are classified under those headings and their main features are described.