Actuarial Notes

Payment

Study guides: Exam FAM, Exam RET-101

The payment Y (the insurer's payment) is the amount an insurer actually pays a policyholder after all policy adjustments — deductible, coinsurance, and benefit limit — are applied to the raw loss X.

Y = \min\!\big(c\,(X - d)^+,\ u\big)

  • X is the ground-up loss, d the deductible, c the coinsurance factor, and u the benefit limit (maximum payment).
  • (X - d)^+ = \max(X - d,\ 0) applies the deductible; multiplying by c applies coinsurance; the outer \min caps the payment at u.
  • This is the payment random variable whose expectation drives premium and reserve calculations.

Expected Payment with a Deductible A loss X is uniformly distributed on [0, 1000] with a $200 deductible and no other adjustments. Find E[Y].

Answer Here Y = (X - 200)^+: zero for X \le 200, and X - 200 for X > 200.

\begin{align*} E[Y] &= \int_{200}^{1000} (x - 200)\,\frac{1}{1000}\,dx \\ &= \frac{1}{1000} \cdot \frac{(800)^2}{2} \\ &= \frac{640{,}000}{2{,}000} = 320 \end{align*}

The insurer expects to pay $320 per loss after the deductible.