How does normative institutionalism explain why political leaders follow informal rules?

Normative institutionalism explains that political leaders follow informal rules based on their perception of what is appropriate or inappropriate for their specific role.1

Unlike other approaches that may focus on self-interest or habit, this perspective emphasizes the internal sense of duty or professional standards associated with a position. When a leader adheres to an informal norm, they do so because they believe it is the "proper" behavior for someone in their capacity, regardless of whether that action serves their personal interests or future career prospects. For example, a minister might resign following a departmental crisis to uphold an informal norm of accountability, viewing such an act as the appropriate response for their office.1