The following are the most common types of referendums held in countries across the world:
Mandatory or obligatory referendum
A mandatory or obligatory referendum is a vote of the electorate which is called automatically under circumstances defined in the constitution or in the legislation. The consequences of the vote are usually binding. Therefore, if a proposal passes, the government or appropriate authority is compelled to implement it. Mandatory referendums may be required in relation to pre-determined issues. Typically, these are issues of major national significance, for example, adoption of international treaties, transfer of authority to international bodies, and taxes and public expenditure commitments. In addition, in many countries, proposed amendments to the constitution must be affirmed by a referendum.
Alternatively, mandatory referendums may be required in pre-determined situations. One example is in Presidential systems, where in the case of disagreement between the President and the Legislature, a referendum may be required to resolve the dispute.
Optional or facultative referendum
The second category of referendum is the optional or facultative referendum. These are votes of the electorate which are called by a formal demand, which may emanate from the executive, from a number of members of the legislature, from a number of citizens or from some other defined agent. The consequences of the vote may or may not be binding. A government can decide to initiate a referendum on a major political issue. It might do so because public pressure for a referendum forces it to hold one, or it might choose to hold a referendum because it is divided on the issue at hand. Optional referendums initiated by the government have been held frequently in Europe on the issue of European Union integration (although in some cases, such referendums have been mandatory because they involve an amendment to a country's constitution). Although these referendums may not be legally binding, it may be politically difficult for a government to ignore the outcome.
A further type of optional referendum is the abrogative referendum. An abrogative referendum is a vote of the electorate which may decide to either retain or repeal a law or decree that has been agreed and promulgated by the legislature and already implemented. Usually, citizens force a vote by collecting a certain number of signatures in support of a vote .
