The advantages and disadvantages of multimember districts mirror those of single-member districts and overlap with the debate over plurality or majority systems and proportional representation systems. The focus in this section will be solely on the advantages and disadvantages of multimember districts as compared to single-member districts.
Advantages of Multimember Districts
The most often cited advantages of multimember districts are that they:
- can more easily reflect administrative divisions or communities of interest within the country because there is flexibility with regard to the numbers of representatives per district and, therefore, the size and geographic composition of the district;
- need not change boundaries, even if the population of a district increases or decreases, because the number of representatives elected from the district can be altered;
- are essential for achieving proportional representation, although not all multimember district systems produce proportional representation for political parties;
- tend to produce more balanced representation by encouraging the nomination of a diverse roster of candidates.
On the last point, there is a good deal of evidence to suggest that women are more likely to be elected from multimember districts. Ethnic, religious and different language groups also tend to be better represented in multimember districts because political parties strive for an overall balance when selecting candidates. The consequences of multimember districts are less certain, however, for groups that are concentrated within a given territory. In the United States, in particular, blacks and Hispanics are more likely to be elected from single-member districts, in large part because the U.S. Voting Rights Act encourages the creation of districts where these racial or ethnic minorities predominate. For a more detailed discussion of the issue of single-member districts and minority representation in the United States, see this link.
Disadvantages of Multimember Districts
The primary disadvantages are that multimember districts
- dilute the relationship between representatives and voters;
- dilute the accountability of individual representatives.
Conclusion
The strength of multimember districts rests in their ability to generate more balanced representation, both for certain groups traditionally under-represented, such as women and ethnic minorities, and for political parties. The degree to which multimember districts are able to do this, however, depends on both the magnitude of the districts and the voting rules employed. The larger the district magnitude, the more proportional the election outcome for political parties. But voting rules also matter. For example, block voting within multimember districts will actually produce more electoral distortion than plurality first-past-the-post voting in single-member districts. Only multimember districts with large magnitudes and some form of proportional voting will consistently produce proportional election outcomes.
