Semi/Moderated Parliamentarism: A fourth model of Separating power

Semi-parliamentary government is a distinct executive-legislative system that mirrors semi-presidentialism. It exists when the legislature is divided into two equally legitimate parts, only one of which can dismiss the prime minister in a no-confidence vote. This system has distinct advantages over pure parliamentary and presidential systems: it establishes a branch-based separation of powers and can balance the ‘majoritarian’ and ‘proportional’ visions of democracy without concentrating executive power in a single individual.

Moderated parliamentarism is a sub-type of semi-parliamentarism. Its centrist 'confidence and opposition' chamber (elected on a moderated majoritarian process such as approval vote or ranked-choice/preferential vote system) supplies confidence to the government and provides a platform to the opposition's government-in-waiting. The diversified 'checking and appointing' chamber (proportionally elected) checks the government & makes constitutional appointments.