I am the control policy. I chose verbs freely (Approach B from the prompt's two-step option: a compact run — match, then a typed transport with an explicit reconcile against the meta-model, then evaluate-fit on the loser). I called the encyclopedia tools throughout.

## Working

### match (retrieve)
Anchored the problem with a domain-stripped meta-model query: "a chooser cannot observe a hidden type of each counterparty; the worst types are the most motivated to participate; design terms so that the act of choosing reveals the hidden type."

- `search_prime` returned **adverse_selection** (0.698) at the top, with its near-family **screening** (distinctive, 0.83 percentile), **signaling**, **price_discrimination**, **mechanism_design**, **incentive_compatibility**.
- `search_by_facets` (5 facets) fused to **adverse_selection** first, then **risk_pooling**, **moral_hazard**; archetype side surfaced **hidden_type_screening**, **incentive_compatible_rule_design**, **payoff_restructuring**, plus a "uniform stricter threshold" facet that landed on **threshold / type_i_type_ii_errors / engineering_tolerances** — i.e., a blunt cutoff, not a type-revealing device.

This is a textbook pre-contractual hidden-characteristic problem, not hidden-action (moral hazard) — the type is fixed and known to the applicant before admission.

### operative primes / salience-rank
- **adverse_selection** — load_bearing. It names the exact failure both approaches must beat: under uniform terms, willingness-to-participate rises with the type that is worst for the uninformed side, so the pool skews bad. Removing it changes nothing about the recommendation only if the second criterion (don't turn away good applicants) is dropped — so it is the frame.
- **screening / incentive_compatibility** — load_bearing. Names Approach A precisely: a menu whose options each type self-selects into, revealing type through the choice, satisfying incentive-compatibility (no type wants to mimic another). This is the *separating* response.
- **threshold / type_i_type_ii_errors** — context. Names Approach B: a single uniform bar. It is a pooling response that trades only on a one-dimensional proxy and cannot distinguish two applicants who sit on the same side of the cutoff but differ in hidden type.
- (pruned: signaling — that is the informed side's move, not the program's; price_discrimination — same structure, wrong substrate.)

### transport (typed: framed → lift-roles → map → lower-to-homolog) of the screening/separating pattern
Pattern roles → situation:
- uninformed designer → the admitting program
- informed agents with hidden type → applicants (low-risk / high-risk)
- menu of type-differentiated options → Approach A's terms (an option only worthwhile to low-risk; or a requirement cheap for low-risk, costly for high-risk)
- incentive-compatibility constraint → each type's best choice is the one the program wants → choice reveals type
- the *pooling* alternative (single price/threshold to all) → Approach B

The correspondence holds cleanly; no role is dropped. The hidden characteristic is a *type* (fixed trait), so the device that works is one that conditions on a CHOICE correlated with that type — exactly screening's logic. A uniform bar conditions only on a single observed proxy; it does not elicit a type-revealing choice.

### reconcile (apply each candidate's logic to the concrete model AND the meta-model separately)
- **Concrete model.** Approach B (uniform stricter bar): raising the bar for everyone rejects marginal *low-risk* applicants (who are over the bar's proxy threshold for reasons unrelated to risk) AND still admits high-risk applicants who clear the same proxy. The success criterion is two-sided: pool not dominated by undisclosed high-risk AND low-risk not needlessly turned away. A uniform bar can only buy the first by sacrificing the second — it has one knob and two targets. Approach A: the separating menu admits low-risk applicants on terms they accept and the high-risk decline (or accept on protective terms), so it can satisfy both targets at once because it has type-conditional knobs.
- **Meta-model.** Same conclusion, stripped of domain: one instrument that conditions on a non-type proxy cannot separate two latent classes that overlap on that proxy; an instrument that makes each class *choose differently* can. The two views agree — but they agree for a reason the meta-model makes load-bearing and the concrete view alone could hide: it is the *dimensionality match* between instrument and the hidden variable, not the strictness of the bar, that decides the case. (The views do not collapse: the concrete view's temptation is "just set the bar high enough," which the meta-model refutes — a higher bar is still one-dimensional.)

### evaluate-fit (gate Approach A's anti-signatures, since A is the front-runner)
From hidden_type_screening's anti-signatures and screening's "what_it_is_not":
- "Relevant attributes already known/verified" → NOT tripped (type is hidden; that is the premise).
- "Decision cheap and reversible" → NOT tripped (admission is a committing, pool-affecting decision).
- "Screen cannot be validated / measures paperwork, wealth, polish rather than the attribute" → CONDITIONALLY tripped — the real risk for A. A separating menu only works if the cost/benefit differential of the options actually tracks *risk* and not merely *resources*. The design must use a requirement that is genuinely cheaper for low-risk to meet (correlated with the hidden type), not one that simply filters the well-resourced. With that proviso the gate is passed; absent it, A degrades into a regressive proxy and A's advantage evaporates.
- "Primary problem is behavior after protection (moral hazard)" → NOT tripped (pre-admission selection).

Approach B's gate: a uniform bar's anti-signature is precisely that it cannot satisfy a two-sided criterion when the proxy and the hidden type are imperfectly correlated — which is the stated situation. B is structurally dominated on the second success criterion.

### STOP
No operative prime is missing from the model; the separating pattern's components (hidden-attribute hypothesis, type-differentiated menu, incentive-compatibility, error/fairness policy) all map to named target mechanisms or are flagged (the validity proviso). The decision is sound: Approach A, conditioned on the menu's differential actually tracking risk.

===DECISION_BEGIN===
DECISIVE_FACTOR: A single uniform bar has one lever but two targets and cannot both keep out hidden high-risk applicants and avoid rejecting good low-risk ones, whereas terms that make each type choose differently reveal the hidden trait and serve both targets at once.
CHOICE: A
JUSTIFICATION: Because you cannot see who is risky and the riskiest are the keenest to apply, any one-size bar set high enough to keep them out will also reject many genuinely low-risk applicants who happen to fall short on the same crude measure. Offering options engineered so that low-risk applicants find one worthwhile and high-risk applicants do not lets people sort themselves, so their choice reveals what you cannot observe directly. This admits the low-risk pool while screening out the high-risk without a blunt across-the-board penalty. The one caution is to design the differentiating requirement so it genuinely tracks risk rather than merely favoring wealthier or better-prepared applicants.
===DECISION_END===
