Rule: treat any documented information edge as temporary rent, not permanent moat

Rule. Frame information-asymmetry edges as rent extracted while the data is proprietary, with explicit decay assumptions. Reject "permanent moat" framings in editorial.

Why. Levin (Levin (Stanford) — making private information public unambiguously improves trade; the edge erodes as data diffuses) — making private information public unambiguously improves trade, i.e., the asymmetry shrinks as data diffuses. Concretely demonstrated in Tesco / Computing on dunnhumby sale — "Using CRM data from loyalty cards is now common practice rather than the unique differentiator that it once used to be": the same Tesco data leadership now says loyalty-card CRM is "common practice rather than a unique differentiator." The mechanism that gave Tesco its 1990s edge has commoditised.

How to apply. Pair any information-edge claim with a decay assumption: how long before this becomes parity? What's the competitive half-life? If the answer is "indefinitely," the framing is wrong — re-examine. Cross-references the moat brief (Research brief: Public data as a private moat — building proprietary intelligence from government open data (piece 11 of 15)) without re-deriving it.