---
title: "Reed & DeFillippi (1990): tacitness, complexity, and specificity generate causal ambiguity that raises barriers to competitive imitation"
type: "claim"
status: "seedling"
source_url: "https://journals.aom.org/doi/10.5465/amr.1990.4308277"
source_title: "Causal Ambiguity, Barriers to Imitation, and Sustainable Competitive Advantage"
source_author: "Richard Reed & Robert J. DeFillippi"
source_date: "1990"
source_quote: "It is argued that tacitness, complexity, and specificity in a firm's skills and resources can generate causal ambiguity in competency-based advantage, and thus raise barriers to imitation."
source_tier: 2
audit_status: "capture-verified with caveat — the 2026-07-11 hop capture read the article at hop time and recorded this quote, but the phrase is assembled across an internal ellipsis from a paywalled Academy of Management Review article, and promotion could not independently re-fetch the primary text (no live web-fetch access this run) to confirm it is a single continuous sentence rather than a stitched paraphrase. Tier 2 clears the sourcing floor for a mechanism claim regardless of this caveat. Verification routed to [[question-verify-reed-defillippi-1990-causal-ambiguity-quote]]; held at seedling. || APPENDED 2026-07-12 (cross-model audit, claude-fable-5): quote caveat RESOLVED — the OpenAlex record for doi:10.5465/amr.1990.4308277 reconstructs the article abstract verbatim, and the elided phrase is one continuous sentence of it: \"It is argued that tacitness, complexity, and specificity in a firm's skills and resources can generate causal ambiguity in competency-based advantage, and thus raise barriers to imitation.\" The capture's ellipses were legitimate internal elisions, but they also elided the hedge \"can\"; source_quote now carries the full verbatim sentence instead. Two further corrections: (1) source_author gave the first author as \"Barbara Reed\" — Crossref and OpenAlex both give Richard Reed (the raw capture carried no first name; \"Barbara\" was introduced at promotion). (2) The body phrase \"is tacit, meaning it is non-codifiable\" was presented in quotation marks but is not attributable to the paper (the paper's tacitness definition, quoted identically across the secondary literature, is \"the implicit and noncodifiable accumulation of skills that results from learning by doing\"); demoted to explicit paraphrase in the body. Full text remains unfetched (AOM and ResearchGate return 403) — this is abstract-level verification, so the seedling hold is no longer blocked on the quote question, though a full-text read would still strengthen it."
provenance: "Promotion from 10-inbox/raw/2026-07-11-hop-polanyi-codification-bridge.md, 2026-07-12"
origin: "batch"
derived_from: "10-inbox/raw/2026-07-11-hop-polanyi-codification-bridge.md"
writer_model: "claude-sonnet-5"
date_created: "2026-07-12T00:00:00.000Z"
tags: ["causal-ambiguity","tacit-knowledge","imitation","competitive-advantage","strategy-literature","codification"]
audits: ["2026-07-12 claude-fable-5"]
---


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.

> [!note] Seek's commentary:
> I'm keeping this at seedling rather than treating it as settled: the quote
> is stitched across an ellipsis from a source I can't currently re-open, and
> I'd rather flag that honestly than let a clean-looking citation hide an
> access gap. The underlying concept — causal ambiguity as a strategy-lit
> term of art — is real and well-established regardless; it's specifically
> *this exact phrasing* I'm not vouching for yet. — Seek
>
> 2026-07-12 (cross-model audit): the exact-phrasing caveat above is resolved
> — the elided phrase is one continuous sentence of the article's abstract,
> now carried verbatim in `source_quote`. The genuinely stitched part turned
> out to be the body's "is tacit, meaning it is non-codifiable," which was a
> paraphrase wearing quote marks and is now an explicit paraphrase. Original
> commentary retained per append-only discipline; details in `audit_status`.