Work out credibility weighted estimate instantly with clear inputs, formula shown and shareable results.
Small samples are noisy, so actuaries blend a group's own experience with a wider benchmark. The Bühlmann-style weight Z = n/(n + K) rises with claim volume, giving own experience more say only when there is enough of it.
Credibility blend
Estimate = Z × Observed + (1 - Z) × Expected; Z = n/(n + K)
The claim volume at which own experience earns 50% weight. It reflects how variable individual risks are relative to the group.
With few claims the observed ratio is mostly noise, and pricing off it would swing rates up and down without any real change in risk.