Parliamentary and presidential regimes differ on whether executive and legislature depend on each other

Evidence

A pure parliamentary regime in a democracy is a system of mutual dependence: (1)The chief executive power must be supported by a majority in the legislature and can fall if it receives a vote of no confidence. (2) The executive power (normally in conjunction with the head of state) has the capacity to dissolve the legislature and call for elections. A pure presidential regime in a democracy is a system of mutual independence: (1) The legislative power has a fixed electoral mandate that is its own source of legitimacy. (2) The chief executive power has a fixed electoral mandate that is its own source of legitimacy. These necessary and suffi- cient characteristics are more than classificatory. — Gary Goertz, Social Science Concepts, 511

Categorization

• DEFINE: Mutual dependence versus mutual independence defined by two necessary-and-sufficient features each: survival rules and electoral mandate.