The 1998 Agreement established a power-sharing system of government, based on a consociational model of democracy. Arend Lijphart designed this model for societies emerging from conflict, or those with the potential for conflict. Switzerland, Belgium and Lebanon also have consociational systems.

The main features of the Northern Ireland model are:

  • cross-community power sharing at executive level, including the joint office of First Minister and deputy First Minister, and a multi-party executive. The First and Deputy First Ministers, one unionist and one nationalist, have equal powers. One cannot be in position without the other. The multi-party executive (cabinet), or coalition, is made up of unionist and nationalist parties. The d’Hondt system determines the proportion of unionist and nationalist Ministers appointed to the Executive, based on the number of seats a party wins in the election.
  • proportionality – a PR (proportional representation) electoral system called Single Transferable Vote (STV) is used to elect Members of the Legislative Assembly (MLAs). D’Hondt is used to allocate positions of power: Executive ministers, as mentioned above and, within the Assembly, the chairs and deputy chairs of committees.
  • cultural equality for the two main traditions (for example the development of both the Irish language and Ulster Scots).
  • special voting arrangements give veto rights to the minority. Certain Assembly decisions require cross-community support - not just majority support but the support of a certain percentage of nationalists and unionists. These decisions include:
    • election of the Speaker and Deputy Speakers;
    • changes to the rules of the Assembly, known as Standing Orders;
    • budget allocations and other financial votes;
    • determination of the number of Ministers and their responsibilities;
    • exclusion of ministers or members of political parties from holding office; and
    • petitions of concern (30 MLAs can request that any decision be taken on a cross-community basis).