Estimation of Policy Liabilities Flashcards
Benktander Ultimate as 2nd Iteration of BF Procedure
U_GB = C + q*U_BF
Benktander Ultimate as Weighting of CL and Expected Ultimate Loss
U_GB = (1 - q^2)U_CL + (q^2)U_0
Benktander Reserves as Weighting of CL and BF Reserves
R_GB = (1 - q)R_CL + qR_BF
Advantage of Benktander Method over CL and BF
Benktander outperforms CL and BF in many situations, with MSE close to optimal credibility reserve.
Advantage of CL over BF and Benktander
With BF and Benktander, different actuaries may arrive at different results because of subjectivity in selecting U_0.
Individual Loss Ratio Reserve Estimate
R_ind = q*C/p U_ind = C/p
Collective Loss Ratio Reserve Estimate
R_coll = q*EP*ELR U_coll = C + q*EP*ELR
Credibility-Weighted Loss Ratio Reserve Estimate
R = ZR_ind + (1 - Z)R_coll
Credibility Weight for Benktander Reserves
Z_GB = p
Credibility Weight for Neuhaus Reserves
Z_WN = P*ELR
Credibility Weight for Optimal Reserve Estimate
Z_opt = p / (p + sqrt(p)) if Var(U) = Var(U_BC)
Optimal Credibility Weight
f = Var(U) / Var(U_BC) t = (f - 1 + sqrt((f + 1)*(f - 1 + 2p))) / 2 Z_opt = p / (p + t)
Burning Cost of Total Ultimate Claims
U_BC = ELR*EP
Advantage of Collective Loss Ratio Reserve over Traditional BF
Different actuaries come to the same result if the same premiums are used, because judgment isn’t used to select the ELR.
MSE for Credibility-Weighted Loss Ratio Reserve Estimate
MSE = E[alpha^2(U)](Z^2/p + 1/q + (1 - Z)^2/t)q