Butsic Flashcards
Relationship between capital, assets, and liabilities
Butsic
capital = assets - liabilities
Criteria for risk-based capital (RBC) methods (3)
Butsic
- the solvency standard is the same across all classes
- RBC is objectively determined
- ability to differentiate relative riskiness b/w quantifiable measures of risk
Reason that EPD is a better measure of insolvency risk compared to probability of ruin (advantage of EPD method)
(Butsic)
EPD also contemplates severity of ruin
Expected policyholder deficit (EPD)
Butsic
expected value of the difference b/w insurer’s full obligation and actual amount paid
EPD ratio
Butsic
EPD ratio = EPD / expected losses
*always ratio to losses even when assets are risky
EPD when losses are risky (discrete & continuous)
Butsic
discrete: sum where losses > assets of pr(L(i)) * (L(i) - A)
continuous: integral from A to infinity of pr(L) * (L - A) dL
EPD when assets are risky (discrete & continuous)
Butsic
discrete: sum where losses > assets of pr(A(i)) * (L - A(i))
continuous: integral from 0 to L of pr(A) * (L - A) dA
EPD method for capital allocation
Butsic
if the EPD ratio > the target EPD ratio, then increase capital
cannot solve for capital directly, so need to use an iterative process starting with the largest loss or smallest asset producing a deficit & working backwards to solve for A
Modification to the EPD method for capital allocation when assets are risky
(Butsic)
use asset relativities since asset values can change throughout the year
relativity = A(i) / E[A]
EPD ratio when losses are risky, d(L), under a normal distribution
(Butsic)
EPD ratio = d(L) = k * ϕ( -c / k) - c * Φ( -c / k)
where c = capital / E[L]
k = coefficient of variation (L)
EPD ratio when assets are risky, d(A), under a normal distribution
(Butsic)
EPD ratio = d(A) = (1 / (1 - c(A))) * [ k(A) * ϕ( - c(A) / k(A)) - c(A) * Φ( -c(A) / k(A))
where c(A) = capital / E[A] k(A) = coefficient of variation (A)
Standard normal density function and negative values ϕ(-x)
Butsic
ϕ(-x) = ϕ(x) because it is symmetric around 0
Cumulative standard normal distribution and negative values Φ(-x)
(Butsic)
Φ(-x) = 1 - Φ(x)
Capital needed for asset risk relative to loss risk with the same beginning balance sheet & EPD ratio under a normal distribution
(Butsic)
more capital needed for asset risk compared to loss risk
standard deviation of capital will be larger under the risky asset scenario because assets > losses
Most appropriate time to use the normal distribution for EPD ratios
(Butsic)
population with known mean where individual losses are independent
EPD ratio when losses are risky, d(L), under a lognormal distribution
(Butsic)
EPD ratio = d(L) = Φ(a) - (1 + c) * Φ(a - k)
where a = k / 2 - ln(1 + c) / k