The delimitation of electoral districts is a fairly recent phenomenon. Prior to the nineteenth century, the composition of legislatures reflected the view that distinct categories of society (i.e., towns, the clergy, and the nobility) should be represented and not individual citizens. This view of representation led to legislatures based on subdivisions that varied greatly with regard to the size of population being represented.
In the latter part of the eighteenth century, and throughout the nineteenth century, citizens began to demand a broadening of their franchise. These demands were accompanied by the belief that "fair" representation entailed an equalisation of population per representative. The response to this quest for the equalisation of representation was either to vary the number of legislators elected from a territory or to subdivide territories into electoral districts of more equal population. Single-member districts for the election of legislators were first adopted in the British colonies that later became the United States. Many European countries gradually followed suit and adopted single-member electoral districts during the nineteenth century.
The trend towards single-member districts in Europe ebbed with the advent of proportional representation in the late nineteenth century. Because multimember districts are generally used with systems of proportional representation, countries that adopted such systems no longer needed to delimit electoral districts. Instead, equality of population could be achieved by varying the numbers of legislators from a territory. The use of administrative divisions such as states, provinces, or counties as multimember districts also provided the additional benefit of community representation.
The tradition of single-member electoral districts was retained in other countries, however, in the belief that distinct benefits are derived from their use. These benefits include:
- a strong geographic link between constituents and their representatives;
- the ability of constituents to hold individual representatives accountable;
- the tendency of an electoral system using single-member districts to produce strong single-party governments, and, by extension, a stable political system.
A major drawback to the use of single-member districts is that electoral district boundaries must be adjusted periodically to maintain populations of relatively equal size. Of course, in some countries, multimember districts must also be redrawn. Not only is the district delimitation process expensive and time consuming, but there is also the possibility that drawing new district boundaries could favour, intentionally or unintentionally, one particular interest or political party over others.
In some countries, multimember districts are also redrawn. How electoral districts are drawn, whether the districts are single-member or multimember, and whether they follow existing administrative boundaries or not can influence the nature of representation by elected legislators. This section considers the various types of electoral systems that delimit electoral districts (see Electoral Systems that Delimit Electoral Districts). It also considers electoral districting alternatives, such as the magnitude of the districts and whether or not the district boundaries should be aligned with pre-existing administrative boundaries (see Electoral District Alternatives).
Delimiting Electoral Districts