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Cost of Insurance
Article published
in the Society of Actuaries'
Product Development Section News
March 1998
Substandard Lives:
Cost of Insurance Charges for Unbundled Products.
Mathematics You Can Use
By: Johan L. Lotter
How good is your
market conduct when you deal with substandard lives? If you are
determining substandard extra cost of insurance charges for Universal
Life or Variable Universal Life policies on the numerical rating
system, you may be using the following formula to determine your
current and guaranteed charges:
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------------------------A
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Where
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is the substandard
monthly cost of insurance rate
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is the standard
monthly cost of insurance rate
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e
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is an expense
loading adjustment (often implemented as zero)
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100k
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is the extra
mortality per cent on the numerical rating system
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Your
reasoning may be that the above is consistent with the numerical
rating system as interpreted by the following equation:
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----------------------------------B
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Where
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is the "substandard"
mortality rate,
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is the "standard"
mortality rate
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You
may feel uncomfortable about the practice as described above because:
a)
You may have questions about the application of the numerical rating
to some vague "standard" mortality rate, since "standard"
would have different meanings for different companies, yet the underwriting
manuals used by companies are often produced by reinsurance companies,
and are not company "standard specific".
b)
You may also be aware that equation B above breaks down for large
values of k at high ages, yielding a paradoxical result when
q'x , which is a probability, exceeds unity.
If
you are aware of the paradox mentioned in b) above, you may have
adopted a practical approach where you have set an arbitrary condition
such as the following:
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-------------------------------C
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Implementation
of C sidesteps the untenable consequence that the risk charge exceeds
the sum at risk at high ages. But it remains unscientific, theoretically
unsatisfactory and unfair from the policyholder’s point of view:
First,
at some time before the maturity date, C sets, on an annual basis,
the risk charges close to the annual sums at risk, leading to visibly
excessive cost of insurance charges.
Second,
B implies that a life, having survived to age x, can have zero probability
of attaining age x+1, a result which many would regard as not scientifically
defensible.
Third,
C almost forces the policyholder to surrender before the maturity
date. This could lead to adverse tax and other consequences for
the policyholder and to eventual dissatisfaction.
Actuaries
cannot afford to regard the potential problems caused by the above
“popular” approach as only becoming “real” at some point in the
distant future: the mere fact that the policy was issued with treatment
implied by equation B, could lead to current market conduct questions.
The
problems posed by implementation of equations A, B and C above,
referred to hereafter as the “popular" approach, are readily
eliminated by a more satisfactory theoretically "correct"
approach. In what follows, we demonstrate how:
·
The “correct” approach leads to a consistent, scientifically viable
and useful treatment of substandard extra mortality at all ages.
·
The “popular” approach can be reconciled with the “correct” approach
if it is acknowledged that the “popular” approach is a “first order”
approximation to the “correct " approach”.
It
is helpful to recognize that:
a)
When the actuary is concerned with the equitable treatment of impaired
lives, "own-company" relative mortality is at issue, absolute
mortality is not.
b)
The numerical rating system was devised to express relative mortality.
It furnishes no information about absolute mortality.
c)
In respect of any portfolio of insured lives, relative mortality
can be measured without knowing anything about the absolute mortality
of the lives being studied.
d)
A sensible way of measuring relative mortality would be simply to
compare relative survival ratios of (1) those lives considered by
the insurance company as sub-standard risks and (2) those lives
considered by the company as acceptable at standard rates, appropriately
striated.
e)
A straightforward method, involving the least number of assumptions,
would be to avoid making assumptions about expected deaths and to
“count” survivors among lives classified as standard risks at issue
and (striations of) lives not so classified.
Such
“count “ would enable the actuary to directly measure relationships
such as D below, where the substandard one-year survival rate is
expressed as the standard rate, raised to an exponent, (1+m); i.e.
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--------------------------D
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Where
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is the one-year
survival rate for impaired lives
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We observe that m
is a useful measure of the relativity of one-year survival rates
and that, if m = 0, the one-year survival rate for the impaired
class is equal to the one-year survival rate of the standard class.
If m is greater than zero, it has the effect of reducing the one-year
survival rate.
Equation
D immediately leads to equation E below, which can be written in
the form of equation F.
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-------------------------E
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--------------------------F
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Equation
F enables ready calculation of substandard mortality rates for any
age and any m.
It
is instructive to consider F after binomial expansion as in G hereunder:
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-------------------------G
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If
we ignore powers of qx greater than unity and substitute k for m in G, G
reduces to B (the "popular" approach). For
large m and qx , however, the second term on the right hand side of G
is significant and, when ignored, leads to the problems and anomalies
inherent in the "popular" approach.
Once
one appreciates that B leads to a logical “dead end”, and that assignment
of a 100k per cent numerical extra rating really means replacing
m with k in D, E, F or G above, the numerical rating is clarified
with respect to its meaning and application and one can immediately
see that the “popular” approach is a first order approximation to
the “correct ” approach.
The
"correct" approach can be implemented as set out below:
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------------H
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Where
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a(x,k)
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is an adjustment
"extracting" excess expense loadings (if any) in the cost
of insurance rates.
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While
the "correct" approach is scientifically and logically
defensible, the "popular" approach is not. In traditional
products, the premiums calculated on the "correct" approach
do not differ very much from those on the "popular"approach.
In unbundled products, the deficiencies of the "popular"
approach are completely and embarrassingly visible. The "popular"
approach can lead to policyholder dissatisfaction when cost of insurance
deductions approach the magnitude of the sums at risk. The correct
approach avoids potential market conduct difficulties.
The
above analysis applies in a much wider sense than cost of insurance
charges for universal life policies and variable life policies.
It is applicable whenever actuaries deal with substandard mortality
under a numerical rating system.
October
16, 1997.
Johan
L. Lotter FIA, ASA, MAAA
(Johan
Lotter is a consulting actuary and President of Lotter Actuarial
Partners Inc., New York)
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