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IAI Actuarial Core Principles · Economic Modelling · Ruin theory

Claims are exponential with mean Rs 5 lakh, and θ = 0.25. Using ψ(u) = (1/(1+θ)) exp(−θu/((1+θ)μ)), what is the adjustment coefficient R, and which is the correct value of ψ(u) when u = Rs 25 lakh expressed as 0.8·e^(−x)?

R is 0.04 per lakh and ψ(25) = 0.8e^(−1). R = θ/((1+θ)μ) = 0.25/(1.25×5) = 0.04, and multiplying by u = 25 gives an exponent of 1.0.

  1. AR = 0.04 per lakh, x = 0.5
  2. BR = 0.04 per lakh, x = 1.0Correct
  3. CR = 0.05 per lakh, x = 1.25
  4. DR = 0.05 per lakh, x = 0.8
  5. R = 0.25 per lakh, x = 6.25

Explanation

R = θ/((1+θ)μ) = 0.25/(1.25×5) = 0.04 per lakh. Then x = Ru = 0.04 × 25 = 1.0, so ψ = 0.8e^(−1). Using R = θ/μ = 0.05 ignores the (1+θ) factor and is wrong.

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