Lock-in effect

A lock-in effect occurs when a system becomes trapped in a suboptimal configuration because the cost of switching to a superior alternative exceeds the benefit. The effect is a structural property of systems with network externalities and positive feedback, where early adoption advantages compound into barriers that no individual agent can overcome. Lock-in is not market failure but path-dependent rationality: each agent's locally optimal choice produces a globally suboptimal equilibrium that only collective coordination can escape.

The lock-in effect is not an accident of history but a theorem about systems with memory. Any system in which adoption generates positive feedback will eventually reach a state where the cost of rewiring exceeds the benefit of improvement. The QWERTY keyboard is not a cautionary tale. It is a proof.