Portfolio Minimum-Viability Rule¶
Procedure — instantiates Cyclic Dominance Counterbalancing
A rule that maintains enough representation of each option so temporary losers do not disappear before the cycle turns.
A Portfolio Minimum-Viability Rule sets a floor under each strategically relevant option — a minimum level of capacity, capability, or representation that the option is never drawn below, no matter how badly it is losing right now. Its defining move is that the floor is not about fairness or equal allocation; it is insurance against irreversibility. An option is protected in proportion to how slow, costly, or impossible it would be to rebuild after the cycle turns — so the rule quietly refuses to eliminate the current loser that will be the next counterweight, while still letting the mix tilt hard toward whatever is winning today.
Example¶
A regional utility runs three kinds of generation that counter one another under different regimes: gas peakers (cheap and flexible when fuel is cheap), hydro (cheap until a drought), and nuclear baseload (steady and immune to fuel-price spikes but slow and expensive to build). With natural gas historically cheap, the finance office wants to mothball the hydro and nuclear plants that look uneconomic quarter after quarter. The minimum-viability rule stops the drawdown at a floor: keep at least a defined firm-capacity minimum of each type online and staffed. The justification is not sentiment but rebuild latency — a retired nuclear unit takes the better part of a decade and billions to replace, and it cannot be summoned when the next gas-price spike or drought arrives. So the rule holds a nuclear and hydro floor through the cheap-gas years, lets gas run well above its floor while it wins, and preserves the counter-capacity the grid will need when the regime flips.
How it works¶
- Fix the repertoire first. Decide which options are genuine, strategically relevant counters — excluding decoys and permanently dominated options — since only real counter-options earn a floor.
- Set a floor per option. For each, define the minimum viable representation: the smallest scale at which the option stays alive, staffed, and re-scalable.
- Peg the floor to rebuild cost, not current performance. The harder and slower the option is to reconstitute, the higher its floor — irreversibility, not popularity, sets the number.
- Separate floor from active weight. The floor says never below this; the rotation policy is still free to run an option far above its floor when it is winning. Enforce the floor against drawdown pressure explicitly.
Tuning parameters¶
- Floor level per option — how much capacity to guarantee. Higher floors are safer against regime change but cost more to carry idle.
- Rebuild-latency sensitivity — how steeply the floor rises with reconstitution time. Weighting latency heavily protects the slow-to-rebuild options but concentrates spending on a few of them.
- Carrying-cost budget — the total the portfolio will spend holding floors. A tight budget forces hard choices about which options are worth insuring.
- Relevance threshold — how strong an option's counter-role must be before it earns a floor at all, guarding against protecting everything.
- Floor review cadence — how often floors are re-justified, so an obsolete option's floor is retired rather than carried forever.
When it helps, and when it misleads¶
Its strength is that it prevents the one truly unrecoverable error in a cyclic field — eliminating the option you will need next — and it keeps counter-capacity warm and re-scalable instead of gone. It converts "keep it just in case" into a defensible, sized commitment.
Its failure mode is that floors look like pure waste in the present, and set too high or too broadly they become diversity-cost creep: every option gets a floor, the carrying costs compound, and the portfolio slowly dies of insurance premiums. The idea has a real analogue in conservation biology's minimum viable population — the smallest headcount below which a population slides to extinction — and the same tension applies: protect too little and you lose the option, protect too much and you starve the rest.[n1] The classic misuse is an advocate dressing up a genuinely dominated pet option as a "counter-option" to win it a permanent floor. The guarding discipline is to grant floors only where a pairwise audit confirms a real counter-relation, peg the height to honest rebuild latency, and sunset floors that no longer earn their keep.
How it implements the components¶
coexistence_viability_floor— the rule is the floor: it defines and enforces the minimum representation that keeps each temporary loser from being eliminated.option_repertoire— it operates over the curated option set and decides which of those options are relevant enough to earn a floor.switch_cost_and_latency_boundary— floor heights are pegged to the cost and latency of rebuilding an eliminated option, so irreversibility sets the insurance level.
It does not map who beats whom — that ledger is Cyclic Payoff Table's — nor decide when to activate an option; the conditional rotation logic belongs to Countermove Rotation Playbook, and the drift signals that trigger re-weighting to Adaptive Mix Review.
Related¶
- Instantiates: Cyclic Dominance Counterbalancing — it supplies the preservation guarantee that keeps the whole cycle viable across regime shifts.
- Consumes: Pairwise Dominance Audit — the audit certifies which options are genuine counters worth a floor.
- Sibling mechanisms: Beats-Relation Matrix · Cyclic Payoff Table · Countermove Rotation Playbook · Pairwise Dominance Audit · Adaptive Mix Review · Sentinel Option Trial · Nontransitive Scenario Simulation
Editorial Notes¶
Form Classification¶
Form family: Rule, Policy & Commitment
Rationale: Portfolio Minimum-Viability Rule operates as a standing rule, threshold, contractual commitment, or policy constraint governing future conduct because it a rule that maintains enough representation of each option so temporary losers do not disappear before the cycle turns.
Independent corroboration: The frozen evidence defines Portfolio Minimum-Viability Rule as 'A rule that maintains enough representation of each option so temporary losers do not disappear before the cycle turns', so its operative form is Rule, Policy & Commitment.
Review outcome: Independent reviewer agreement; high confidence.
Origin Attribution¶
Primary origin: Biology & Ecology
Origin pattern: Cross-disciplinary synthesis
Present-day reach: Multi-domain
Rationale: Maintaining all competitors in a cyclically dominant set imports ecological coexistence and frequency-dependent competition logic.
Related originating lineages:
- Economics & Finance — Finance contributes diversification and option-preservation practice.
- Operations Research — Maintaining option floors under carrying-cost and regime uncertainty is fundamentally a constrained portfolio and robust-allocation rule.
- Organizational & Management Science — Organizational portfolio management supplies the governed retention rule.
Review resolution: Light authoritative-source research resolves the primary-origin disagreement in favor of biology ecology. PNAS: Coexistence in Diverse Communities with Higher-Order Interactions directly documents the defining practice or theory described in the selected origin rationale. Other domains are retained only where the blind reviews identify material co-development or translation; broad application is recorded separately as domain_reach=multi_domain, while origin_mode=cross_disciplinary_synthesis describes the relationship among origin lineages.
Attribution caveat: The boundary with operations research is substantive because that tradition materially developed or translated part of the mechanism; the cited provenance places the defining form in biology ecology.
Encyclopedia synthesis: The exact catalogued form synthesizes established practice rather than reproducing a single standard historical label.
Review outcome: Researched adjudication after independent review; medium confidence.
Sources consulted:
Notes¶
[n1] Minimum viable population — in conservation biology, the smallest population size below which a species is likely to slide to extinction from ordinary demographic and environmental variation. It is the direct analogue of a viability floor: the point of preserving a minimum is not to keep the option large but to keep it from crossing the threshold of no return. ↩