CONCEPT
Path Dependence
The principle that where you are constrains where you can go—decisions already made narrow the set available next, investments already sunk cannot be recovered, and rational choices compounded over time produce outcomes choosers would not have selected if they could see the full trajectory.
Path dependence is not merely the truism that history matters. It is Arthur's precise claim that the sequence of decisions creates channels—grooves, ruts—in the landscape of possibility, and the deeper those ruts, the costlier it becomes to climb out. Every year of investment in a technology stack, a programming paradigm, a professional identity deepens commitment to a basin of attraction that may be collapsing. The senior engineer who mastered a particular stack made rational choices at every step; the accumulation of those choices is now a trap. Path dependence operates at multiple levels simultaneously: technical lock-in (languages, frameworks, tools), institutional lock-in (org structures, hiring practices, curricula), and psychological lock-in (professional identity, community membership, status hierarchies). Arthur's framework reveals the cruelty of lock-in breaking: the expertise was real, the skills genuinely hard-won, and none of it provides automatic leverage in the new paradigm.
In The You On AI Field Guide
Arthur