Expected loss equals claim frequency multiplied by average severity.
纯保费 = 理赔频率 × 平均赔付额。
| Item | Formula / Rule | Source / Standard |
|---|---|---|
| Pure premium | Pure premium = claim frequency × average severity, i.e. the expected annual loss | Bowers et al. 1997, Actuarial Mathematics, Ch. 2 |
| Compound model | Aggregate loss S = X1 + … + XN with mean E[S] = E[N] × E[X] | Bowers et al. 1997, Actuarial Mathematics, Ch. 2 |
| Variance split | Var(S) = E[N]·Var(X) + Var(N)·E[X]2, so frequency and severity both drive volatility | Bowers et al. 1997, Actuarial Mathematics, Ch. 2 |