FA-62880 / Insurance premium rating / Member archive

Workers compensation experience modification: Excess credibility weight is applied to the wrong term · case 05

Mods overreact to excess losses and the expected-excess ballast is mostly discarded.

Member previewVariant 5 · 3 implementations · 10 checks per implementation

Case contract

Input expected (cents, >0 else 'invalid expected'), split, weight W (per mille), primary_ratio (per mille of expected that is primary), ballast B, claims [[amount, 'ind'|'med']]. Medical-only claims count at 30%. Each claim splits into primary min(v,split) and excess. mod=(Ap+W*Ae+(1-W)*Ee+B)/(E+B), returned in hundredths rounded half-up.

Why this case matters

Experience rating multiplies manual premium, so a wrong split, weight or reduction shifts an employer's premium.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
mixed claim history 0	`71`	`88`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.