Head of State - Constitutional Models

Constitutional Models

In protocolary terms, states are distinguished as monarchy or republic depending on the style (and usually mode of accession, see below) of their head of state, a typical constitutional provision, but as such this is not defining for the actual political system, which often evolves significantly, or can remain unaltered in other respects despite a transition from monarchy to republic (or, rarer, vice versa).

Different state constitutions (fundamental laws) establish different political systems, but four major types of heads of state can be distinguished:

1. The parliamentary system, with two subset models;
   1. The standard model, in which the head of state, in theory, possesses key executive powers, but the exercise of such power is done on the binding advice of a head of government.
   2. The non-executive model, in which the head of state has either none or very limited executive powers, and mainly has a ceremonial and symbolic role.
2. The semi-presidential system, in which the head of state shares key executive powers with a head of government and/or cabinet; and
3. The presidential system, in which the head of state is also the head of government and has all executive powers.

The same role in a federal constituent and a dependent territory is fulfilled by the corresponding office equivalent to that of a head of state. For example, in each Canadian province the role is fulfilled by the Lieutenant Governor, whereas in most British Overseas Territories the powers and duties are performed by the Governor. The same applies to Australian states, Indian states, etc. Hong Kong's constitutional document, the Basic Law, for example, specifies the Chief Executive as the head of the special administrative region, in addition to his role as the head of government. These non-sovereign-state heads, nevertheless, have limited or no role in diplomatic affairs, depending on the status and the norms and practices of the territories concerned.