SLIDE 23 Ruin and correlation Optimal reserve allocation Sensitivity and robustness New themes Dependence between claim amounts influenced by an environment process
Correlation crises
Dependence between claim amounts, claim size distribution and intensity are modulated by a Markovian environment process. Markov environment process (J(t))t≥0 with J ≥ 2 states 1, . . . , J
◮ with initial distribution π0 ◮ and transition rate matrix Q.
Claim amounts: for 1 ≤ i ≤ n, sequence of i.d. random vectors (X i
m)m≥1 s.t.
∀n ≥ 1, X i
n = I i nW i 0 + (1 − I i n)W i n,
◮ where the (W i
n)n≥0 are i.i.d. r.v.’s with cdf F i W ∈ R−αi ,
◮ the (I i
n)n≥1 are i.i.d. Bernoulli r.v.’s with parameter pi ∈ [0, 1],
◮ the W i
n, n ≥ 0 are independent from the I i k, k ≥ 1
◮ and the W i
n, n ≥ 0 and I i k, k ≥ 1 are independent from a Poisson
process Ni(t) with parameter λi. Define the J independent processes (1 ≤ i ≤ J) as Y i(t) = cit −
Ni (t)
X i
mi
Stéphane Loisel (ISFA, Lyon) QRM in insurance November 2010 19 / 37