Alteration of the form of government is an example of one kind of major substantive shift sometimes undertaken in the course of Constitution building. The magnitude of change is greatest with a move between the extremes of a parliamentary and a presidential system. There are variations in between, however, which can involve significant change as well.
Variations between parliamentary government on the one hand and presidential systems on the other typically involve arrangements in which there is both a leader of the government (Prime Minister) chosen by reference to the composition of the Parliament, and a President with significant power who normally is directly elected. Depending on the respective powers assigned to the Prime Minister and the President, arrangements of this kind may be ranged at different places along the parliamentary/presidential spectrum of possibilities.
Not all aspects of the form of government are set out in the text of the Constitution and much important detail inevitably is left to legislation or political practice, typically during the implementation stage. A change of this kind is so central to the system of government, however, that a framework for it, at least, is always constitutionally provided.
A decision to change the form of government in a substantial way may be influenced by a variety of considerations including dissatisfaction with current arrangements and a perception that restructuring could lead to improvement in stability, effectiveness or representation. Any such change requires care in design and implementation, however, and may have consequences for the structure and operation of politics that are difficult to predict. Where a change of this kind is combined with devolution, as sometimes is the case, it is necessary to consider how the two intermesh as well, in terms of both practice and design.
The case studies explored issues relating to:
- The factors that influenced the decision to make a significant change to the form of government;
- The reasons why it was decided to make a substantive change to the form of government rather than reform the existing presidential or parliamentary system;
- The most difficult questions that arose when designing the changes;
- Challenges for implementation;
- The sources of comparative models and other international influences brought to bear; and
- What might have been done differently in hindsight and insights for other countries dealing with similar issues.