The Picken Complete Taxonomy for AI Governance: A Unified Instrument Framework for Board-Level AI Governance Assessment, Liability Pricing, and Sector Contagion Modelling

AI governance research has, to date, developed largely as a series of independent instruments, each addressing a discrete failure mode — regulatory exposure, vendor credibility, sector-specific liability — without a unifying framework describing how these instruments relate to one another or to a shared theoretical foundation. This paper presents the first complete taxonomy of the Picken Diamond instrument family: twenty-two instruments, organised into three tiers, unified by a single five-pillar governance assessment and a shared mathematical philosophy of inverting established financial risk theory onto board-level AI governance. The taxonomy demonstrates that these instruments are not a loose toolkit but a coherent measurement system, progressing from point-in-time organisational assessment (Tier One), through extended decision-support and post-deployment evaluation (Tier Two), to sector-level contagion projection across time (Tier Three). In plain terms: this is the map that makes the family's existing structure visible for the first time — of the twenty-two instruments described, eleven have prior standalone publication; the remaining eleven were developed and calibrated within the author's working methodology and are described here for the first time. The paper's contribution is structural rather than computational — it describes what each instrument measures and why, situating the family within the wider AI governance and financial-risk-theory literatures, without disclosing the proprietary calibration methodology by which any individual instrument's output is derived.