Coalition government

A coalition government, or coalition cabinet, is a government by political parties that enter into a power-sharing arrangement of the executive. Coalition governments usually occur when no single party has achieved an absolute majority after an election. A party not having majority is common under proportional representation, but not in nations with majoritarian electoral systems.

There are different forms of coalition governments, minority coalitions and surplus majority coalition governments. A surplus majority coalition government controls more than the absolute majority of seats in parliament necessary to have a majority in the government, whereas minority coalition governments do not hold the majority of legislative seats.

A coalition government may also be created in a time of national difficulty or crisis (for example, during wartime or economic crisis) to give a government the high degree of perceived political legitimacy or collective identity, it can also play a role in diminishing internal political strife. In such times, parties have formed all-party coalitions (national unity governments, grand coalitions).

If a coalition collapses, the prime minister and cabinet may be ousted by a vote of no confidence, call snap elections, form a new majority coalition, or continue as a minority government.

For a coalition to come about the coalition partners need to compromise on their policy expectations. One coalition or probing partner must lose for the other one to win, to achieve a Nash equilibrium, which is necessary for a coalition to form. If the parties are not willing to compromise, the coalition will not come about.

Before parties form a coalition government, they formulate a coalition agreement, in which they state what policies they try to adapt in the legislative period.

In multi-party states, a coalition agreement is an agreement negotiated between the parties that form a coalition government. It codifies the most important shared goals and objectives of the cabinet. It is often written by the leaders of the parliamentary groups. Coalitions that have a written agreement are more productive than those that do not.

If an issue is discussed more deeply and in more detail in chamber than what appears in the coalition agreement, it indicates that the coalition parties do not share the same policy ideas. Hence, a more detailed written formulation of the issue helps parties in the coalition to limit 'agency loss' when the ministry overseeing that issue is managed by another coalition party.