What does path dependence mean in historical institutionalism?

In historical institutionalism, path dependence refers to the concept that initial, often contingent, choices made during the creation of an institution significantly constrain the range of future options available to political actors.12

This process suggests that once a specific path is selected—such as choosing private over public pension provision—actors invest in adapting to that structure. This investment creates feedback mechanisms that "lock in" the institution, making it durable and resistant to change, even if the original choice was not the most efficient or optimal one.31

Key aspects of path dependence in this context include:

• Contingency: Early decisions are often influenced by chance or specific historical circumstances that could have led to different outcomes under alternative initial conditions.1
• Constraint: Once established, institutional rules and structures limit the behavior of actors, often leading to inertia where significant policy changes occur only in exceptional situations.12
• Feedback Mechanisms: These can be institutional (where rules prevent certain actions) or cognitive (where policy makers view the world through a limited perspective), both of which reinforce the existing trajectory and discourage deviation.1

Essentially, path dependence highlights that "history matters" because past institutional decisions create a legacy that shapes and limits contemporary political outcomes.12