Reed & DeFillippi (1990): tacitness, complexity, and specificity generate causal ambiguity that raises barriers to competitive imitation

Reed & DeFillippi, "Causal Ambiguity, Barriers to Imitation, and Sustainable Competitive Advantage" (Academy of Management Review, 1990), name the mechanism by which firm-specific know-how resists being copied by rivals. Three properties of a skill or routine — tacitness, complexity, and specificity — combine to generate causal ambiguity: an outside observer (or a rival trying to reverse-engineer the advantage) cannot cleanly identify which inputs actually produce the valuable output. Where much of the success-relevant knowledge in a firm's routines is tacit — noncodifiable skill accumulated through learning by doing rather than expressible as explicit rules — that ambiguity itself becomes the barrier to imitation, and the advantage persists.

This is the imitation-side counterpart to the automation-side claim in claim-polanyis-paradox-tacit-tasks-resist-automation: both papers identify non-codifiability as the property doing the work, applied to different actors (a machine trying to execute the task vs. a rival trying to copy it). The synthesis of the two is observation-codification-is-the-shared-hinge-of-automation-and-imitation. It also grounds the strategy-literature side of claim-euv-mirror-advantage-is-tacit-know-how-not-patent, which currently rests only on a Tier-4 industry explainer for its own mechanism claim — this note supplies the Tier-2 theoretical backing that explainer lacked.