Because delimitation, or redistricting, practices vary greatly around the world, there are few universal principles to guide the delimitation process. Countries disagree on fundamental issues, such as how impartial and independent the process can and should be from the legislative and political concerns. But there are several generally accepted principles:
- representativeness;
- equality of voting strength;
- independent, impartial boundary authority (or, at a minimum, reciprocity);
- transparency;
- non-discrimination.
Representativeness
Electoral district boundaries should be drawn such that constituents have an opportunity to elect candidates they feel truly represent them. This usually means that district boundaries should coincide with communities of interest as much as possible. Communities of interest can be defined in a variety of ways. For example, they can be geographically defined communities delineated by administrative boundaries or physical features such as mountains or islands, or they can be “communities” that share a common race, ethnic or tribal background, or the same religion or language. If districts are not composed of communities of interest, however defined, it may be difficult for representatives to serve the constituency well.
Equality of Voting Strength
Electoral district boundaries should be drawn so that districts are relatively equal in population. Equally populous districts allow voters to have an equally weighted vote in the election of representatives. If, for example, a representative is elected from a district that has twice as many voters as another district, voters in the larger district will have half the influence of voters in the smaller district. Electoral districts that vary greatly in population--a condition referred to as "malapportionment"--violate a central tenet of democracy, namely, that all voters should be able to cast a vote of equal weight.
The following are two standards developed to reflect this principle, one offered by the Organization for Security and Cooperation in Europe (OSCE) and one by the UN Committee on Human Rights (UNCHR):
- The delineation of constituencies in which elections are conducted must preserve the equality of voting rights by providing approximately the same ratio of voters to elected representatives for each district. Existing administrative divisions or other relevant factors (including of a historical, demographic, or geographical nature) may be reflected in election districts, provided the design of the districts is consistent with the equality of voting and fair representation for different groups in society. (OSCE, “Inventory of OSCE Commitments and Other Principles for Democratic Elections”)
- The principle of one person, one vote must apply, and within the framework of each State’s electoral system, the vote of one elector should be equal to the vote of another. The drawing of electoral boundaries and the method of allocating votes should not distort the distribution of voters or discriminate against any group and should not exclude or restrict unreasonably the right of citizens to choose their representatives freely. (UN Committee on Human Rights, General Comment 25, “The Right to Participate in Public Affairs, Voting Rights and the Right to Equal Access to Public Service”)
Independent, Impartial Boundary Authority
Ideally, the legal framework for boundary delimitation should provide that the persons or institution responsible for drawing electoral boundaries be independent and impartial. In addition, the recommendations of the boundary authority should not be subject to modification or veto by the government or by the legislature.
Failing this, the procedure for delimiting electoral districts should be clearly spelled out in legislation so that the rules regulating the process are the same, regardless of who is drawing the district boundaries – that is, the process should offer reciprocity. If political concerns are permitted to play a role in the process, then all political parties must be given access to the process. These rules must be clearly understood and must be acceptable to all major political parties and participants in the districting process.
Transparency
Because electoral systems that feature districts often produce disproportional election outcomes, it is essential that the delimitation process be considered fair if the result is to be deemed legitimate by stakeholders and voters. This means that the delimitation process should be as transparent as possible, with the methodology and guidelines clearly established and publicised in advance. Incorporating public hearings into the process to allow stakeholders to offer comments for the boundary authority to consider is also important.
Non-Discrimination
Electoral boundaries should not be drawn in a manner that discriminates against any particular minority group. For example, dividing a geographically-concentrated minority group among several electoral districts so that the group constitutes a minority of the voters in every single electoral district should be prohibited. Of course, electoral systems that rely exclusively on single-member districts cannot guarantee even some minimal percentage of seats for minority groups or minority political parties in the population. However, this fact should not open the door to active discrimination against a given minority group.