TRANSACTIONS OF SOCIETY OF ACTUARIES
1980 VOL. 32
PRICING A SELECT AND ULTIMATE ANNUAL
RENEWABLE TERM PRODUCT
JEFFERY DUKES AND ANDREW M. MACDONALD
ABSTRACT
This paper discusses the special considerations involved in pricing a
select/ultimate annual renewable term product. It covers such areas as
expenses, conversion costs, and profit calculation, and devotes particular
attention to the relationship between mortality and withdrawals on this
type of product. A general equation for computing the extra mortality
under various lapse assumptions is developed.
INTRODUCTION
H
IGH interest rates in recent years have led increasingly to a
"buy term and invest the difference" strategy among insureds.
Insurance companies, like all competitive businesses, must
shape their products to fit the desires of their market. This need, com-
bined with the increasing emphasis on term insurance, has intensified
competition for the term insurance sale. Many companies hope that their
term sales will result in conversions to permanent plans, but some view
the term market as a profitable end in itself. In this market there is no
competition keener than that for annual renewable term (ART)--or
yearly renewable term (YRT). A few years ago, some of the innovative
smaller companies began marketing a select and ultimate ART (S/U
ART) product. Having just completed the pricing of such a product,
which, we believe, could well become the top term product in most port-
folios, we felt it might be helpful to discuss our methods and provoke
some discussion within the profession.
PRODUCT DESCRIPTION
The usual ART product (which we call the aggregate ART) has
annually increasing premiums that vary by attained age only. As the
name implies, S/U ART has annually increasing premiums that vary by
issue age and duration since underwriting. For the first few durations
after underwriting, premiums are quite low; these durations constitute
the select period, which generally lasts four or five years, although,
547
548 SELECT AND ULTIMATE RENEWABLE TERM
beginning in late 1979, products with a one-year select period began
appearing on the market, and products with select periods of ten or
fifteen years are not unheard of. While the logical select period would
seem to be the select period inherent in the mortality table used for
product pricing, in practice one sees the range mentioned above.
At the end of the select period, the insured will pay premiums from the
ultimate rate scale; these premiums vary only by attained age. The
insured can seek to avoid paying these higher ultimate rates by exercising
the reversion feature usually found in S/U ART plans. This feature
gives the insured the opportunity at the end of the select period (or
earlier for some of the products with long select periods) to provide new
evidence of insurability at the company's expense; if the insured is still
a standard risk, a new policy is issued at the select rate for the new
issue age. The annually revertible (one-year select period) products of
which we are aware have less stringent requirements for reversion. The
insured may only have to answer three or four questions about his
health in the past year. Presumably, much of the excess mortality over
that of a new issue is offset by reduced underwriting costs.
The reversion process can be repeated as long as the insured remains
a standard risk and below a specified age (typically 70). In the case of a
reversion, the agent usually receives a commission equal to 50-100
percent of the first-year commission for a new issue. In this paper, we
will examine S/U ART products that require full evidence of insurability
for reversion and that pay a full first-year commission to the agent
upon reversion. Table 1 compares aggregate ART and S/U ART rates
(five-year select period) for issue age 45.
PRICING ASSUMPTIONS
Mortality and Lapses
These will be treated together, since we believe they are intimately
connected and are of fundamental importance in pricing this product.
We will assume that lapse and mortality experience is available for an
aggregate ART plan and that we are attempting to produce premiums
for an S/U ART product. Any lapses in excess of the corresponding
aggregate ART lapses will be called "reversions." Insureds who do not
revert will be called "persisters." We will start with two examples,
which we will then expand into a generalized formula for computing
mortality rates.
Suppose, for the first example, that we have a select and ultimate
ART product with a five-year select period. In pricing the product, we
assume that lapses in years 1-4 and in years 6 and over are the same as
SELECT
AND ULTIMATE
RENEWABLE TERM
549
those for aggregate ART (that is, no reversions occur in those years);
however, to consider the reversion feature, we assume that there is a
single reversion of 50 percent of the survivors at the end of year 5 and
that these "reverters" are all standard risks. (These "lapses" due to
reversion at the end of year 5 are assumed to be in addition to the normal
lapses that might be experienced on an aggregate ART where there is
less incentive to lapse to obtain a lower premium.) It should be noted
that this is not a realistic assumption, since insureds could revert and
obtain a lower premium before the end of the select period either with
another company or with the same company if such a practice were
allowed. Nevertheless, let us assume now, for simplicity, that the only
reversions occur at the end of the fifth year.
TABLE 1
COMPARISON OF RATES FOR S/U ART AND AGGREGATE ART
] S/U ART
J
Isstre Aoo~- ]" Select Yesrs Ultimate Years
GATE
ACZ ART
45 ..........
46 ..........
47
..........
48
..........
49 ..........
50 ..........
51 .........
52 ..........
53 ..........
54 ..........
55 ..........
56 ..........
57 ..........
58 ..........
59 ..........
60 ..........
61 ..........
62 ..........
63 ..........
64 ..........
65 ..........
66 ..........
67 ..........
68 ..........
69 ..........
70 ..........
71 ..........
72 ..........
73 ..........
74 ..........
75 ..........
76 ..........
77 ..........
78 ..........
79 ..........
1 2 3 4
4.86 2.98 4.13 5,70 6.92
5.31
5.79
6.33
6.91
7.56 3.83 5.84 8.31 10.42
8.25
9.05
9.86
10.75
11.74 5.03 7.87 12.23 16.08
12.88
14.13
15.46
16.93
18.54 7.67 11.36 18.59 25,18
20.26
22.14
24.08
26.12
28.77 13.19 18.83 29.13 38.60
31.42
34.15
37.25
40.80
45.77 21.88 29.24 43.32 [ 54.21
51.44
5793
65.23
73.28
81.37
90.46
100.59
110.75
123.90
5 Attained Rate
Age
8.15 50 9.45
51 10.31
52 11.31
53 12.33
54 13.44
12.53 55 14.68
56 16.10
57 17.66
58 19.33
59 21.16
19.96 60 23.18
61 25.33
62 27.68
63 30.10
64 32.65
31.77 65 35.96
66 39.28
67
42.69
68 46.56
69 51.00
48.06 70 57.21
71 64.30
72 72.41
73 81.54
74 91.60
74.96
75
101.71
76
113.08
77 125.74
78 138.44
79 154.88
550 SELECT AND ULTIMATE RENEWABLE TERM
Assume, then, that qf,j+t represents the aggregate ART mortality rate
and
(qP)r~+t
the mortality rate for the persisters on a select and ultimate
ART product. Because it is assumed that those who revert must meet
full standard underwriting requirements for a new issue, those who
revert at the end of policy year n will "start over" with mortality rate
(qr)tI~l+,]+~. Under our assumption of full underwriting at reversion,
(qr)t[xl+,]+t =
qtz+,l+t, where x + n is the age at reversion. In addition,
we assume that the total deaths experienced by the reverters and per-
sisters will equal the total deaths that would be experienced by a group
of the same size on an aggregate ART product. We also assume that the
underlying lapse rates (apart from the reversion rate) for reverters and
persisters are the same and are equal to those of an aggregate ART plan.
These assumptions lead to three conclusions:
1. (qP)r,~+t = qf.j+t
for t < 5. This follows from the assumption that lapse
rates are the same for both the aggregate ART and S/U ART products
before the end of the fifth year. It also assumes that there is no additional
antiselection on an S/U ART and that underwriting standards are the same
for both products.
2. (qP)tzl+t
> qt.l+t for 5 _< t < 5 + (select period in pricing mortality table).
This follows from the assumption that the 50 percent that leave the popula-
tion through reversion at the end of year 5 are all standard risks, indicating
that the persisters have a mortality rate higher than that of the comparable
aggregate class.
3. (qP)|zl+, = ql~l+t for t > 5 + (select period in pricing mortality table).
This follows from the assumption that total deaths for persisters and
reverters equal total deaths under an aggregate ART product. Thus, after
the effects of selection assumed in the pricing mortality table have worn
off, persisters and reverters experience the same mortality rates.
These conclusions will be seen more clearly in the development of
the formulas needed to calculate (qP)izl+t- To develop those formulas,
we add the following definitions to those we already have:
/t,l+t = Total number of survivors t years after issue at age x
= Total number of reverters and persisters at duration t.
(lp)i,~+t
= Number of persisters at duration t after issue at age x.
(lr)Nxj+,j+t
= Total number of survivors t years after reversion at age
x + n, where the original issue age was x. Note that a
distinction is being made between, say,
(It)H351+51+,
(which
represents total survivors t years after reversion at age
40 for issue age 35) and ll,01+, (which represents total
survivors t years after issue at age 40).
W
qt*l+* = Aggregate ART lapse rate at duration t.
SELECT AND ULTIMATE RENEWABLE TERM
dt~l+ t =
(@)~,1+,
=
(dr) u,~+.l+t =
(dr)~+.~+, =
Note that all
551
Total number of deaths between durations t and t + 1
after issue at age x
Total number of deaths among reverters and persisters
between durations t and t + 1.
ltzl+tq~=l+t.
Number of deaths among persisters between durations t
and t + 1 after issue at age x.
l ~'
( P)t~l+tq[~l+t"
Number of deaths between durations t and t + 1 after
reversion at age x + n.
l,+t functions are calculated as l~+t = l~+t_l - d,+t_x -
d~-t-1,
where dz~+t reflects expected lapses under an aggregate ART
product. Similar formulas apply to the calculation of
(lp),+,
and
(lr)~-t.
Note also that the rate of lapse, q~+t, is assumed to be the same for
persisters and reverters.
Given these assumptions and definitions, the following formulas
emerge (see Appendix I for a comparison of aggregate ART mortality
and S/U ART persister mortality as produced by these formulas).
First,
(lr)[c,l+51
= 0.5/f=j+5,
(lp)~,l+5 =
0.5/~=j+5,
Second,
qf,7+5l:~]+5 = (qp)[~]+5(lp)t=j+5
+
(qr)ff,j+5~ (lr) tE~l+~ ,
(qP)
~,~+5 = qt,l+~/t~l+5 --
(qr) tt=l+sl (lr)
tt,l+~l
(lp)~,~+~
= /t,~+~(qt,~+~ -- 0.5q[~+5~) since (qr)[f,]+~l = q[,+~]
0.5/[~1+~
= 2q~,~+.~- q[~+~].
Third,
Thus,
where
and
d[zl+e =
(dP)t~l+6 +
(dr)[t~l+~l+l.
q~zl+el[~]+8 = (qp)t~7+~(IP)~1+6
+
(qr)fm+5]+l(Ir)[r~+~l+~ ,
(lp) E,I+8 = (lp)t~1+5[1
--
(qp) ~1+5 --
qr'~J+5]
(Ir) ff~+sJ+l = (Ir)[~,l+sj
(1 -- qt[,J+sl -- q[~l+5) •
552
SELECT AND ULTIMATE RENEWABLE TERM
Thus,
(qp)~.~+, =
qt,~+*l[~'~+~ --
(qr)tt.l+~l+a(lr)tI~,~+sl+~
(lp)[.l+s[1
--
(qp)~.l+s
-- q(~l+~]
= q[~1+6l~..|+6 -- q[.~+~7+l(lr)r[.l+~l~-x
(lp)
I.~+~[ 1 --
(qp)txl+5 -- qI~l+5]
'
since
(qr)it,~+b~+~
= qt~-n~+a.
Fourth, in general, for t >_ 6,
(qP)
t.l+t =
q~.j+,lc.j+~ -- qr.+~+~_~(lr),.~+~+,_~
(~P)~+,
where
and
(lp) t~]+,
=
(lp) r.1+t_l[1
--
(qp) t.]+,_l --
qi'~l+t-al]
(lr) tt=l+51+t_5
=
(lr)[t~l+51+,_e[1
--
(qr) tt~1+51+t_6
-- q[~l+,-t] •
Fifth, for t > 5 + (pricing mortality select period),
q~x7+t = (qr)~j+51+e-5 ---- qc~+sJ+~-s = q~+~
---- Ultimate pricing mortality.
Thus,
(qP)t.l+* = q*+'[/f'J+'- (/r)fl.j+~j+,_~]
(lp)
E.I+,
Since total deaths and withdrawals for reverters and persisters under an
S/U ART product are the same as total deaths and withdrawals under
an aggregate ART product,
d[.l+, --
(dp)l~l+t + (dr)[[~l+Sl+t-5
and
which implies
or
dt'.]+t
(dP)t,]+, + ,o
= ~, (dr) [~l+51+t_~,
It.j+, = (lp)t.j+, + (lr)tfxj+sj+,_5,
(lp) cxl+, = lt.l+, --
(tr) ti.l+~l+,_5.
Thus the equation in the fifth statement above reduces to
(qp)Exi+t-~
qx+t.
Two observations are in order. First, it is not necessary to consider
further reversions among the reverters when calculating
(qP)~xl+t.
This
follows from our basic observation that the total number of deaths for
a group of policyholders is the same regardless of how the group is split--
SELECT AND ULTIMATE RENEWABLE TERM 553
a sort of conservation-of-total-deaths principle. The basic components
in the calculation of
(qP)c~l+~
are (1) deaths in the (t + 1)st policy year
from the entire group of policies issued at age x, namely,
d~+t,
and
(2) deaths among reverters, namely,
C
(~)
co.,+.,+,-. •
n=1
The conservation-of-total-deaths principle implies that deaths among
persisters in the (t + l)st policy year equals (1) - (2). The point of the
observation is that none of the terms of the sum in (2) is affected by
reversions after the reversion that gave rise to the term in the first place.
This follows from applying the conservation-of-total-deaths principle to
each group of reverters, (/r)[txl+~l+t-,, giving rise to the terms in (2). An
analogue to the conservation-of-total-deaths principle can be found in
the conservation-of-total-momentum principle of physics. Picture a
particle, T, moving along with momentum Mr. Suddenly T splits into
two particles, R (as in reverter) and P (as in persister), with momenta
MR and
MR,
respectively. Then MR + Mp - Mr. If one knows Mr and
Mm one can calculate Mp. If R splits into two or more fragments, we
know that the momenta of the fragments add up to the momentum of
R, so consideration of the fragments adds nothing but unnecessary
complication to the computation of Mp.
The second observation is that the more reverters there are, the higher
(qP)[x]+t
will be. This is intuitively obvious, since when a closed group
loses its better risks, the mortality for those remaining clearly will be
worse than that for the group before the loss.
The second observation leads to some real pricing headaches. The S/U
ART products currently on the market generally have minimum issue
amounts of at least $100,000. Consequently it seems reasonable to assume
that the insureds who purchase these products are on the whole fairly
sophisticated and likely to take advantage of situations that will decrease
their cost. In other words, one would expect reversions before the limiting
date specified in the policy form. Thus our simple assumption of 50
percent reversions at the end of year 5 with no earlier reversions is
probably unrealistic. These reversions before the end of the select period
create higher than aggregate ART mortality in the remaining select
years and decrease the number of insureds over which expenses can be
amortized, thus leading to a steeper premium scale. But the steeper the
premium scale, the greater the advantage to be obtained by applying
for a new select rate. In other words, pessimistic assumptions have a
tendency to be self-fulfilling (at least on paper--we have no experience
554 SELECT AND ULTIMATE RENEWABLE TERM
to go by). One way to combat this problem would be to offer an n-year
renewable and convertible term product such that, at the end of n years,
the product would be renewable at a relatively low rate if satisfactory
evidence of insurability were provided, but at a relatively high rate if
no evidence were furnished.
Another problem with an S/U ART product is that slightly substan-
dard cases in the ultimate years may prefer to lapse the S/U product
and purchase an aggregate ART product rather than pay ultimate
premiums. Such lapses further steepen the premium scale and ex-
acerbate the problem mentioned above of steep premiums causing higher
lapses leading to higher mortality and yet higher premiums. Let us hope
this is a convergent sequence.
If it is assumed that there will be reversions before the end of the
select period, the expected mortality rates will be affected. Suppose, as
our second example, we assume the following pattern of reversions:
1. No one reverts in policy years 1 and 2.
2. 30 percent of the survivors revert at the end of policy year 3.
3. 10 percent of the survivors revert at the end of policy year 4.
4. 20 percent of the survivors revert at the end of policy year 5.
In the authors' view, this pattern of reversions probably is more realistic,
given the mobile nature of the middle- and higher-amount term market.
We again assume that these reversions are in addition to the normal
lapses that one might expect in the case of an aggregate ART product.
We also assume that all of these reversions are standard risks.
Under this set of assumptions the following formulas would emerge
(see Appendix II for a comparison of aggregate ART mortality and S/U
ART persister mortality produced by these formulas).
First,
(lr),~+.~l
= 0.3/~,~+3,
(lp)rxj+3
= 0.71c,7+3,
where/t~]+~ is some convenient radix;
(dr) it,l+31
=
(qr)(t~]+s] (lr)frx1+31 ,
(dp) cxl+3
=
(qP) fxJ+3(lP)t~l+3,
d(~]+~ = q[~l+3lt~l+a •
Since d[~l+3
=
(dr)tt,l+a ] + (dp)[~]+~ , then
q[~l+alt~l+s =
(qr)(t~]+~l (lr)(txl+al
+
(qP)[~]+3(lP)(~+3,
(qP)(~l+~
= q[~]+31[,]+~ -- qt~+3l(lr)[~,l+al
(lp)~,~+~
because (qr)tt~]+a] = q[,+31 •
Second,
SELECT AND ULTIMATE RENEWABLE TERM 555
d W ,
(lr)[txl+41 =
O.l[(lp)txl+s- (dP)txl+s- (
p)[,l+s]
d to
(lP)t,~+4 = 0.9[(lp)t,l+z-
(dp)t~+3- (
P)tx~+~]
/[:el+4 = /[x]+s -- di:el+Z -- d~izl+z,
(Ir) t[xl+s]+l
=
(Ir) trzl+aj
-- (dr)[tz]+sl -- (dr)Tt~]..~l •
Since dt,l+a--
(dp)t,.l.¢4 +
(dr)it,~+aj+x +
(dr)tt,~+4j
for both deaths and
withdrawals, then
qtzl+41rz]+4 = (qP)[z]+a(lP)
[.z]+4 "3i-
qt,+3l+l(lr)[tz/+3/+l
-~
qtz+41(lr)[[z]+4]
,
because (qr)tt~l+31+~ = qt~+~l+~ and (qr)tt~l+41 = qt~+41. We then solve for
(qP)t~-~, which is the only unknown.
Third,
d to ,
(lr)tr=j+z I
= 0.2[(lp)[,]+a-
(dp)[x]+4 -- (
P)b~]+4]
d to ,
(lp) t,~+~
= 0.8[(lp) t,~+4 -
(dp)t,~+4
-- (P) t,1+4]
/[zl+s = /[z1+4 -- d[xl+4 -- d~[zl+4 ,
rto
(lr)
~t~l+4]+t =
(lr)tt~]+41
--
(dr)t[~l+4l
-- (d)tt=l+4l ,
(lr),t.j+31+~
=
(lr)t~,j+31+l
--
(dr)tt,j+sj+x
-- (dr)Tt,l+3l+x •
Since dt.l+ 5 = (dP)t~l+5 + (dr)tt.]+~l+l + (dr)tiz]-~]+2 + (dr)ttx]+5] for both
deaths and withdrawals, then
qt,l+~l[~l+5 =
(qP) t,l+s(lP)
t~]+5 +
qv,+4l+l(lr) tt~]+4l+a
+ q[~+~+~(lr)
t[~]+~+~ + qt~+~l
(lr)t[~l+~
•
We then solve for (qp)[,]+n, which is the only unknown.
Fourth, for l >_ 6,
(Ip)t,]+, = (lp)v~l+t-x- (dp)[~l+t-x- (dp)~,l+t-~,
(lr)[t~l+4]+t-4 = (lr)[t,~]+4]+t-~- (dr)[[zl+4]+t-s-
(dr)7[~]+,l+t-~ ,
(lr) tt~l+z~+t_z
=
(lr) tt~]+z]+,_4
--
(dr) tt,l+al+t_4
--
(dr) t~+z~+,_,
,
556 SELECT AND ULTIMATE RENEWABLE TERM
Since d[.]+, ---
(dp)t.j+t + (dr)tt.j+51+e-6 + (dr)H.j+tj+t-4 + (dr)tr.)+aj+t--.
for both deaths and withdrawals, then
qr.J+,/r.)+, =
(qP)1.1+ t(Ip)[.j+,
+
(qr)
rr.J+sj+,-5(/r) r~.l+5~+t-5
+ (qr)tt.i+4]+,-,t(lr)ft~1+aI+,-,t + (qr)tt.~+a1+,-a(lr)tt.~l+zl+,-z.
Fifth, again, for t > 5 + (pricing mortality select period),
q~,j+, =
(qP)t~+t = q,+,.
We are now in a position to develop a generalized formula. Let
qrizl+t_ t
be the proportion reverting (all of whom are assumed to be standard),
and let
q'~x]+t-t
be the normal aggregate ART lapse rate (t = duration
since original issue). Note that we are assuming that
qt~l+t-x
depends
only on duration since original issue at age x for all persisters and revert-
ers arising from that issue age. We are also assuming that all lapses
occur at year-end and that lapses and deaths are independent.
We can then solve for
(qP)t,l+t
as follows:
t
qt.l+tl[.]+, = (qp)t~]+~(lp)t.l+t + ~ qtt~l+.l+t-~(lr)ir.l+.l+t-. ,
n=l
where
and
t-1
w
l[.1+, = lt.1 II(1 - qt.l+. - qt.l+.).
t-I
(lP)I.l+t /t.lII(1
"
1 '* ,
= - qE.1+.)[ - (q/')~.l+. - q[.J+.]
where
(qp)~
= q~.l; and
n~2
a~O
n--1
X 1 -- (qP)t~l+, -- qfxl+,
*=0
t--n--1
× 1 u I, •
#=0
Until experience develops on this product, estimates of percentages
reverting will necessarily be guesses, but the underwriting department
might be able to give some assistance in estimating the percentage of
potential reverters who would still be standard risks at given ages and
durations. An alternative, albeit complicated, method of ascertaining the
SELECT AND ULTIMATE RENEWABLE TERM 557
proportion of persisters who are still standard at a given duration
might be to apply the techniques developed by Richard Ziock in his
paper "Gross Premiums for Term Insurance with Varying Benefits and
Premiums"
(TSA,
XXII, 19).
It probably would be advisable to price S/U ART using two or three
scales of reversion rates. Any such scale probably should have a relative
or absolute maximum for the policy year given in the policy form for
reversion, since both the agent and the insured have a financial incentive
for reversion at that duration. In that year, regardless of the premium-
paying mode, total lapses (which equal aggregate ART lapses plus
reversions) would be skewed toward the end of the year, since all rever-
sions would tend to occur at year-end, Figure 1 shows some of the
possible total lapse patterns that could be assumed. Pattern A assumes
total lapse rates equal to those under an aggregate ART product (that
is, no reversions) until duration 5, when reversions of 50 percent are
assumed. Pattern B assumes the same reversion rate at duration 5 as
Pattern A, but with additional reversions in years 1-4. Pattern C
assumes that the largest reversion rate will occur in year 3, in spite of
the five-year select period, with another large block of reversions at the
end of year 5.
0,6
0.5
0.4
0,3
0.2
0,1
0.0
I I f I I I l
1 2 3 4 5 6 7
Policy Year
Fro. 1.--Possible total lapse rate patterns for S/U ART
558 SELECT AND ULTIMATE RENEWABLE TERM
Conversions and Conz,ersion Single Premiums
Our conversion rate assumptions for S/U ART did not differ from
those used in pricing an aggregate ART product. An argument could be
made for using somewhat higher conversion rates in the ultimate years,
since the differential between the premium for a standard permanent
product and the ultimate S/U ART premium (which for our product was
equivalent to a low substandard aggregate ART premium) might be
small enough to induce extra conversions.
We also made the debatable assumption that the mortality of people
converting their S/U ART to a permanent plan of insurance would be
no higher or lower than the mortality of those continuing with the S/U
ART product. This assumption is consistent with our pricing of other
term plans. Our reasoning was that the S/U ART is renewable well
beyond the last conversion date, at rates significantly below those for a
permanent plan; hence it would be cheaper for an insured in very poor
health to hold onto the term product. Naturally there are gray areas--
people who are in poor health but who are not on their deathbeds might
feel that they should convert while they still have the chance. The
healthier members of the group, however, could equally well decide that
they want permanent coverage, and exercise their conversion options.
In any event, until the duration t is such that (qP)c~]+t = qc~+~ (that is,
while t >_ (S/U ART select period) + (select period in pricing mor-
tality table), the above mortality assumption produces much higher
ultimate-year conversion single premiums (CSPs) than one obtains for
an aggregate ART product. These high CSPs can have a significant
effect on profits or premium levels in the ultimate years. One possible
solution would be to limit the convertibility of S/U ART to the select
years only. To ignore the conversion cost is to assume that the extra
conversion mortality will be borne by the conversion product, which
therefore should be priced accordingly.
Expenses
It is important to account for any extra selection expenses expected in
the year of reversion guaranteed by the policy. One would expect that
virtually everyone would ask to be underwritten if the financial incentive
were great enough (and it probably is for our product, since the company
pays the cost). As a result, the company would expect to incur medical
and inspection costs for nearly the entire group of insureds at that dura-
tion, but only those who are still standard can revert to a new select
rate. Those who revert are priced as new issues; their underwriting
costs will be more than compensated for, because it is reasonable to
SELECT AND ULTIMATE RENEWABLE TERM 559
suppose that all who qualify as standard risks will revert, and because
new-issue underwriting costs are inflated by the not-taken and declination
rates. Thus, in accounting for extra selection expenses, the real question
is whether the percentage of those applying to revert who are not stan-
dard (and thus not allowed to revert) is greater than or less than the
usual not4aken rate for new issues. An additional expense need be
added in the pricing only if it is expected that more people will be declined
for reversion than would decide not to take the policy if they were new
first-time applicants.
Equity
A very real question of equity arises if persisters are required to
amortize acquisition expenses incurred by reverters. In any plan of
insurance, those who continue under the plan are burdened with the
acquisition expense of those who lapse in the early years. However, under
an S/U ART product, this condition is aggravated by the contractual
provision allowing reversions and by commission and premium scales
that encourage reversions before the point called for in the contract.
One approach to this problem would be to discourage early reversions
by making reversions less attractive to the agent. This might be ac-
complished by paying a level commission during the select years. Since
the agent's commission (as a percentage of premium) would be the same
whether the insured continued on the select scale or reverted early,
the agent's incentive to seek early reversions might be reduced. Alterna-
tively, the company could agree to pay only a renewal commission in
cases of early reversion. This also would reduce the incentive to the
agent to seek early reversions, but it would require that the company be
able to detect them. Under this approach, the savings realized by not
paying a full first-year commission for those who revert early would be
used to offset the unamortized original acquisition expense that the
early reverters would otherwise leave behind for the persisters to absorb.
(It is assumed that such savings arise because premiums were calculated
on the basis of full first-year commissions.) An extension of this idea
would be to pay a reduced commission on all reversions, whether early
or not.
Another approach would be to make early reversions less attractive
to the insured. One could require the insured to supply satisfactory
underwriting evidence at his expense in order to apply for a contractual
reversion or an early reversion. Here again, if rates were calculated
assuming full underwriting expenses, the savings could be used to offset
the amount of unamortized initial acquisition expense. This approach
560 SELECT AND ULTIMATE RENEWABLE TERM
might also reduce the number of those seeking to revert. Alternatively,
one could design an S/U ART product with level premiums during the
select period. This would eliminate the incentive to revert early, since
the level premium rate would be higher for higher issue ages.
Unfortunately, many of these proposed solutions may not seem very
practical in the current marketplace. Reducing commissions to the agent
on contractual or early reversions could well result in having reversions
placed with other companies that pay full first-year commissions on new
lives; the company then would realize no savings with which to offset
unamortized acquisition expenses. A similar result might follow from
having reverters pay for their own underwriting. Designing a product
with level select-year premiums is an intriguing idea, but the product
might not be attractive to insureds who can obtain a lower rate in the
early years by purchasing a nonlevel select-year premium product.
Despite these problems, it is the authors' belief that some of the above
measures should be instituted in order to emphasize to agent and insured
alike that early reversions are not desired by the company.
If we assume that some control can be exercised over early reversions,
one further point should be stressed: it is important to preserve equity
between those who revert contractually at the end of the select period
and those who persist beyond the select period. This can be accomplished
in the pricing process by making sure that the asset share at the end of
the select period is sufficient to generate a percent-of-premium profit
roughly equal to that which will be contributed by the persisters over
the expected lifetime of the policy.
Profits
Because of the many uncertainties about the magnitudes of the major
variables needed to price this product, it seems reasonable that one
would want higher than normal profit margins built into the premiums.
Further, we felt that the asset share should be positive at the end of the
select period, even for the most pessimistic lapse assumptions.
Calculation of percent-of-premium profit to be earned over, say,
thirty years for a closed block of new, first-time issues is complicated
by the fact that the policy provides for reversion at the end of the select
period, as indicated in Figure 2. It should be noted that Figure 2 assumes
that reverters before the end of the fifth year (the date the contract
allows reversion) are really lapses and do not contribute to profits.
Let us define the following:
(AS)t,1+, = Asset share per unit in force at the end of policy year t for
issue age x;
SELECT AND ULTIMATE RENEWABLE TERM 561
P~ul+~
= Probability of reverting at the end of a policy select period
of five years;
pr = Probability of surviving all decrements for a t-year period
t [~t
for someone aged y at issue; and
*rt.j+t -- Accumulated premium dollars per unit in force.
Then the total asset share per unit in force after thirty years attributable
to a new issue at age x is
T R I
( AS)~j+3o + ~P[,]P[,I+.~( A S)
[,+sj+~5
T R
q'- sP[~lPf~l+5 +P'~,+51P'~+sI+~( AS)'[~+xol+~o
T R tT tR t
+ • • • + 5PromPt.I+5 • • • 5P c.+2o]P r.+2o]+5(AS) c~+25]+5,
where the primes indicate that the lapse assumptions entering into the
computations for those who have reverted at least once may differ from
the lapse assumptions used for new issues. For instance, in the first five-
year period, lapses might be greater than those given by a blended
pricing assumption pattern; in subsequent (reversion) select periods,
lapses might be expected to be somewhat less than those assumed in the
pricing. Total accumulated premium for the given closed block of business
is computed using the above formula and replacing all
AS's
by 7r's.
JJJ
Years from Original Issue
Y
Fro. 2.--Asset shares for S/U ART
562 SELECT AND ULTIMATE RENEWABLE TERM
Ultimate Premiums at Ages beyond the Last Allowed Reversion Age
If the policy is renewable beyond the last age for which the insured is
allowed to revert, then the ultimate premiums for ages beyond the
maximum reversion age should reflect the fact that the group of insureds
paying these ultimate rates includes an increasing number of standard
risks. If the maximum issue age and maximum reversion age coincide,
then, from the end of the last premium select period onward, one might
expect mortality about equal to that for an aggregate product with the
same maximum age at issue.
ADMINISTRATION AND EXPERIENCE MONITORING
Since lapses have such an impact on mortality rates and expense
amortization, they must be monitored carefully and discouraged when
possible. One question that is certain to arise is, "What do you do if an
insured applies for a new select rate before the allowed reversion date?"
Since reversions are treated as lapses in the asset share, this behavior
increases lapse rates. Our company will not pay the agent a first-year
commission on a new policy resulting from a reversion before the end
of the select period. However, this system is not foolproof; in a brokerage
agency, for example, the broker could have the insured switch back and
forth every year or two between two companies offering S/U ART
products. The insured would get low rates and the agent would pile up
first-year commissions. Discouraging these frequent replacements would
seem to be very difficult. Policies with level premiums and level com-
missions in the select period probably would help a great deal, as would a
good program to detect twisting. A company could also emphasize the
possible disadvantage to the insured of starting a new contestable period
with each replacement.
Although reversions are treated as lapses, it would be useful, for
purposes of refining the pricing assumptions, to know what proportions
are reverting. One also would need to know (a) how many reversion
medicals the company is paying for, as compared with the number
reverting and (b) the usual not-taken rate,
CONCLUSION
We hope that the techniques and considerations presented in this
paper give actuaries some useful ideas for pricing S/U ART and an
awareness of the very real dangers inherent in marketing these kinds of
plans. Emerging lapse experience will take much of the guesswork out
of estimating reversion rates and thus will improve the accuracy of
future pricing. Meanwhile, in our opinion, the best policy would be to
SELECT AND ULTIMATE RENEWABLE TERM 563
price defensively by designing the plan so that there are few incentives
for early reversion. Some of the defensive measures mentioned in the
paper may be hard to market. Given the reversion feature in the con-
tract, the development of ultimate-year mortality rates based on as-
sumed reversion rates is of primary importance. It is the authors' con-
clusion that, because of this reversion feature, ultimate-year premiums
should be substantially higher than either select-year rates or aggregate
ART premiums.
ACKNOWLEDGMENTS
Several useful suggestions were made by the reviewers. Early in our
pricing work, Steve Lewis made a couple of key observations on the
notion of conservation of total deaths. We would also like to thank
Ken Mihalka for his efforts in writing the program to calculate the
modified mortality rates appearing in Appendixes I and II.
APPENDIX I
AGGREGATE ART MORTALITY COMPARED WITH S/U
ART PERSISTER MORTALITY: ALL
REVERSIONS AT END OF YEAR 5
(Issue Age 45)
DURAl'ION
SINCE
Iss~
0 .........
1 .........
2 .........
3 .........
4 .........
5 .........
6 .........
7 .........
8 .........
9 .........
10 ........
11 ........
12 ........
13 .......
14 .......
15 .......
16 .......
17 ........
18 ........
19 ........
20 .......
21 .......
22 .......
23 .......
24 .......
25 .......
26 ........
27 ........
28 ........
29 ........
MORTALITY RATE PER 1,000
Aggregate S/U ART
ART Persister
Mortality Mortality
(i) (2)
1.70 1.70
2.36 2.36
2.99 2.99
3.59 3.59
4.12 4.12
4.66 7.00
5.23 7.01
5.85 7.20
6.53 7.54
7.48 8.43
8.51 9.57
9.68 11.00
11.02 12.72
12.55 14.71
14.34 17.10
16.50 19.98
MODIFICATION
TO AGG~GA~
ART
MORTALITY
1[(2)--(1)1/(1)1
0.0
0.0
0.0
0.0
0.0
50.2
34.0
23.1
15.5
12.8
12.4
13.6
15.4
17.2
19.3
21.1
18.01 21.16
19,69 22.25
21.63 23.48
23.81 24.80
26.17 26.17
28.73 28.73
31.40 31.40
34.21 34.21
36.99 36.99
39.92 39.92
43.46 43.46
47.47 47.47
51.73 51.73
56.43 56.43
17.5
13.0
8.6
4.2
0.0
0.0
0.0
0.0
0,0
0.0
0.0
0.0
0.0
0.0
PERCENTAGE
REVERTING
o%
0
0
0
0
50
o
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Non~.--Test calculations using an underlying lapse rate equal to that for aggregate
ART and using an underlying lapse rate of 0% produced mortality rates only slightly
different from each other.
564
APPENDIX II
AGGREGATE ART MORTALITY COMPARED WITH S/U
ART PERSISTER MORTALITY: REVERSIONS AT
END OF YEARS 3, 4, AND 5
(Issue Age 45)
DURATION
SINCE
Issue
0 ........
1 ........
2 ........
3 ........
4 ........
5 ........
6 ........
7 ........
8 ........
9 ........
10 .......
11 .......
12 .......
13 .......
14 .......
15 .......
16 .......
17 .......
18 .......
19 .......
20 .......
21 .......
22 .......
23 .......
24 .......
25 .......
26 .......
27 .......
28 .......
29 .......
MORTALITY RATE I~ER 1,000
Aggregate S/U ART
ART Persister
Mortality Mortality
(1) (2)
1.70 1.70
2.36 2.36
2.99 2.99
3.59 4.25
4.12 4.89
4.66 5.96
5.23 6.19
5.85 6.56
6.53
7.10
7.48 8.20
8.51 9.43
9.68 I0.81
II .02 12.43
12.55 14.25
14.34 16.37
16.50 18.96
18.01 19.96
MODI ]¢ICATION
"~o AGGREGATE
ART
MORTALITY
I[(2)-(i)I/(D I
0.0
0.0
0.0
18.3
18.8
28.0
18.4
12.1
8.8
9.6
10.8
11.7
12.8
13.5
14.1
14.9
10.8
19.69 20.97
21.63 22.20
23.81 24.05
26.17 26.17
28.73 28.73
31.40 31.40
34.21 34.21
36.99 36.99
39.92 39.92
43.46 43.46
47.47 47.47
51.73 51.73
56.43 56.43
6.5
2.6
1.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
PERCENTAGE
REWarlh'O
0%
0
0
30
10
20
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Nozz.--Test calculations using an underlying lapse rate equal to that for aggregate
ART and using an underlying lapse rate of 0% produced mortality rates only slightly
different from each other.
565
DISCUSSION OF PRECEDING PAPER
TO~[ BAKOS:
One reason for the development of a select and ultimate annual renew-
able term (ART) product that was not mentioned by the authors is to
minimize deficiency reserves. Although the expression "deficiency
reserve" is not used in the 1976 amendments to the standard valuation
law, additional reserves equivalent to what used to be called deficiency
reserves are still required if an ART gross premium is less than some
statutory minimum. These additional reserves can be minimized by
establishing the ultimate premiums of a select and ultimate ART product
at a level that is not deficient. Competition demands, and experience
mortality permits, select premiums much lower than ultimate premiums.
These select premiums probably would be deficient. If the select period
were five years, the anticipated premium stream would consist of select
(probably deficient) rates for the first five years and ultimate (non-
deficient) rates thereafter. Deficiencies would be limited to the first five
policy years, not the entire renewal period, producing a significantly
smaller surplus strain than would be produced by the alternative, a com-
petitive aggregate ART product.
To make what would otherwise be a very uncompetitive product com-
petitive, the reversion feature is added, which allows insureds to re-
qualify for the select rates as described in the paper. Those companies
that adopt a select and ultimate premium structure only as a gimmick
to avoid large deficiency reserves probably would impose minimal under-
writing requirements so as to requalify nearly 100 percent of their policy-
holders at each requalification period. Such companies would have what
the paper describes as aggregate ART products disguised as select and
ultimate products. Those companies that approached the select and
ultimate product more naively and attempted more serious underwriting
would requalify something less than 100 percent and would incur
significant additional expenses that would increase the price of the
product. Both types of companies would lose the competitive advantage
of guaranteed low rates throughout the renewal period. In this sense, a
select and ultimate reversionary product is not as competitive as an
aggregate guaranteed premium product.
Although there may have been other needs that caused the develop-
ment of a select and ultimate ART product, the need to minimize de-
567
568 SELECT AND ULTIMATE RENEWABLE TERM
ficiency reserves was the first that I became aware of, and it is reasonable
to suppose that these other needs developed in an effort to legitimize the
concept. Certainly the need to reduce deficiency reserve requirements
has stimulated other forms of product innovation. For example, we also
have guaranteed maximum premium ART products and participating
ART with an ultimate premium rate structure after, say, the third year.
The dividends for this participating ART begin at the end of the third
year and are mysteriously equal to the difference between the ultimate
and the initial-scale premium.
Another approach to pricing a select and ultimate ART product is
described in the remainder of this discussion. This alternative approach
starts with the principle of conservation of total deaths described in the
paper, but limits its application because mortality and persistency are
felt to unfold in a manner different from that assumed in the paper.
Basic Approach
Take the paper's basic formula that expresses the principle of con-
servation of total deaths at the requalification age [x] + 5,
qi,l+~lt,~+~ = (qP) txl+~(lP)r,l+~ + (qr) trxl+51 (lr) tt,l+51 ,
and rearrange it as follows:
(/r)tt,l+sl
(qr)cf,~+5 T +
(/P)[~1+5
(qp)f,~+5.
qfx]+~ --- /fx]+5 lrxl+5
We know that lt.l+s = (lr)ttxl+~l + (/P)t~l+5, so we can make the following
definitions:
(lp)~.I+5
(/r)c~I+sl and 1 - k~,j+~ =
kr'l+5 = lt~1+5 I[,1+~
where kt~l+5 is the proportion of the age x issues reverting at age Ix] + 5.
Substituting in the rearranged formula yields
qE~]+.~ =
k[xl+~(qr)ttx]+~l +
(1 - kf~l+~ ) (qP)t~l+~,
which we can solve for ki,l+~ as follows:
(qP)t.l+5 - qI,l+~
k[,]+~ =
(qP)c,~+5 -- (qr)~c~+sl "
In their paper Dukes and MacDonald assume that the proportion revert-
ing is 50 percent and then solve for the persister mortality,
(qp).
They
have also assumed that the reverter mortality,
(qr),
is equal to new
select mortality. Their solution for
(qp)
beyond duration 5 depends on
the assumption that lapse rates for the persister and reverter classes are
DISCUSSION 569
identical and that total lapses are the same as for an aggregate ART
product. This assumption seems questionable. The reverters, through the
reselection process, have been determined to be standard. The persisters,
then, are obviously substandard, and the ultimate premium they will be
charged includes, implicitly, a substandard extra. Presumably, under
an aggregate premium structure none of these persisters would have
lapsed for another ART product, since it would be available to them
only on a substandard basis. Why give up a standard rate for a sub-
standard rate? These same persisters, however, when charged an ulti-
mate, implicitly substandard premium, would be prompted to shop.
Those better substandard risks in the persister class probably would be
successful in finding a better aggregate ART rate, even if it were sub-
standard, and they would lapse their policies.
The reverse of this argument could be made for the reverter class, and
it could be asserted that their persistency will be better than that for an
aggregate product. Thus, it is logical to assume that persistency for the
reverter class would be different from that for the persister class and
that, in total, persistency would be different from aggregate ART
persistency.
It should be noted that the persister mortality is just as dependent
upon the assumption made for the proportion reverting as it is upon the
lapse assumption. This was demonstrated in the paper. If these assump-
tions cannot be made reliably, then the persister mortality cannot be
solved for reliably. There is, therefore, no particular advantage in
approaching the problem in this way. Instead, one could establish an
assumption about the level of persister mortality consistent with the
reselection effort planned and the substandard mortality expected, and
then solve for kE,l+5 , the proportion of the age x issues reverting. Thus,
the ultimate ART rates could be set in much the same way that sub-
standard premium rates are set. Knowing the mortality levels under-
lying the ultimate ART rate structure and using ktxl+5 as a guide, the
underwriter could classify the risk as either a reverter (standard) or a
persister (substandard).
In solving for kt.l+6 , the additional assumption would be made that
(qr)cExl+51 = q~+53,
as was done in the paper, and the formula would
become
(qP)M+~ -- q~l+5
All of the assumptions made to solve for kc,j+6 would be made only with
respect to the duration in which the reversion occurred. The value of
570 SELECT AND ULTIMATE RENEWABLE TERM
kt~l+5 would be useful only as a guide in evaluating the reselection
process.
Mortality Assumption
In solving for persister mortality,
(qp),
the paper invokes the con-
servation-of-total-deaths principle, assumes that lapse rates for reverters
and persisters are the same and are equal to those of an aggregate ART
plan, and assumes that reverter mortality is identical with new select
mortality. Under these assumptions, persister mortality and reverter
mortality are related as shown in Figure 1. The curve labeled q shows
the original-issue select and ultimate mortality assumption. The curves
(qp)
and
(qr)
show persister and reverter mortality equaling ultimate
mortality fifteen years after the reversion period.
However, the assumption that reverter and persister mortality each
equal ultimate mortality fifteen years after reversion seems to be only a
pricing convenience. The conservation-of-total-deaths principle is not
infringed if we assume that persister mortality is always greater than
ultimate mortality and that reverter mortality is always less than ulti-
mate mortality, as shown in Figure 2. This assumption seems reasonable
because the reselection process can be expected to weed out the poorer
risks each time it is exercised on the prior reverter class. The reverters
q
I~ ~elect period ~l I
I I
i i
FIO. 1.--Relationship of persister, aggregate, and reverter mortality assumed in
paper.
DISCUSSION
57 l
I " select period : I I
I I
J I
FIG.
2.--Relationship of persister, aggregate, and reverter mortality assumed in
discussion.
remaining after continual reselection might exhibit new select mortality
at the time of reversion, but this select mortality might wear off more
slowly than in an aggregate select class and might settle at a level lower
than aggregate ultimate mortality. Thus, the reverter class can be as-
sumed to be superselect in the sense that the select period it exhibits is
longer than the select period normally assumed in pricing aggregate
ART. To preserve the conservation-of-total-deaths principle, the per-
sister mortality would have to be always greater than the aggregate
ART's pricing mortality. This is consistent with the concept that per-
sisters are really substandard risks.
The formula presented in the paper and modified in this discussion
gives a relationship among
k, q, (qp),
and
(qr)
that holds at all durations
only under the lapse assumption made in the paper. If this lapse assump-
tion is assumed not to hold, then the relationship among these four terms
is not so simple. The complexities of this relationship can be avoided by
assuming that reverter and persister mortality (and persistency) are
independent of each other.
If a requirement of a select and ultimate product is that deficiency
reserves be minimized, then ultimate premiums for the lowest premium
band or class should not be less than 1,000c, computed on the Modern
572
SELECT AND ULTIMATE RENEWABLE TERM
CSO Table at 4½ percent. This would eliminate deficiencies during the
ultimate period in most states. For pricing purposes, the mortality under-
lying these ultimate rates could be estimated in two ways.
Method 1.
The ultimate premium could be "unloaded." Aggregate ART premi-
ums from a current product could be compared at each age with the average
pricing mortality rate for that age to compute a "load." This "load" could
then be applied in reverse to estimate the persister mortality underlying the
chosen ultimate premium.
Method 2.
The substandard rating implied by the chosen ultimate premium
could be determined by relating the ultimate premium to a current aggregate
ART premium. The percentage extra mortality implicit in the ultimate
premium could then be multiplied by the average aggregate ART pricing
mortality rate for each age to estimate the persister mortality underlying the
chosen ultimate premium.
Table 1 shows the solution for the underlying ultimate mortality using
method 1, and Table 2 shows the solution using method 2. The results,
given the crudeness of the processes, are similar and show that the maxi-
mum substandard mortality occurs at age 30 at about the table 4 (200
percent of standard mortality) level. One might want to modify these
underlying rates for two reasons: First, at the higher attained ages they
are less than the ultimate pricing mortality used for the aggregate ART,
and, second, the implied substandard ratio is not level by age.
TABLE 1
C.4LCULATION OF UNDERLYING
ULTIMATE
MORTALITY USING METHOD 1
Age
(~)
15 ...........
20
...........
25
...........
30 ...........
35
...........
40 ...........
45 ...........
50 ...........
55 ...........
60 ...........
65 ...........
70 ...........
Ultimate
Premium
1,000cx
Modern CSO
44%
(2)
1.30
1.68
1.92
2.03
2.27
3.02
4.41
6.67
10.38
16.07
26.78
41.89
Unloading
Ratio*
(3)
0.45
0.45
0.46
0.42
0.50
0.56
0.62
0.64
0.62
0.52
0.42
0.40
Underlying
Ultimate
Mortality
[(2)X(3)1
(4)
0.59
0.76
0.88
0.85
1.14
1.69
2.73
4.27
6.44
8.36
11.25
16.76
Average
Aggregate
Pricing
Mortalityt
(5)
0.52
0.52
0.49
0.45
0.64
1.07
1.87
3.03
4.80
7.06
I0.53
16.10
Implied
Substandard
Ratio
[(4)/(5)]
(6)
1.13
1.46
1.80
1.89
1.78
1.58
1.46
1.41
1.34
1.18
1.07
1.04
*The unloading ratio for each age is the ratio of average prieingmortality to the lowest
premium band
rate,
t This is a weighted average or "aggregate" pricing mortality at each attained age, which recognizes
the distribution of in-force by duration at each attained age.
DISCUSSION 573
TABLE 2
CALCULATION OF UNDERLYING ULTIMATE MORTALITY USING METHOD 2
Age
(1)
15 ..........
20 ..........
25 ..........
30 ..........
35 ..........
40 ..........
45 ..........
50 ..........
55 ..........
60 ..........
65 ..........
Ultimate
Premium
1,000cz
Modern CSO
(2)
1.30
1.68
1.92
2.03
2.27
3.02
4.41
6.67
10.38
16.07
26.78
Aggregate
ART
Standard Rate
(3)
1.03
1,03
1.03
1.03
1.23
1,85
2,90
4,57
7,49
13.11
24, 19
Implied
Substaudard
Ratio*
~1[(2)I(3)-- I]/
o.91+~11
(4)
1.29
1.70
1.96
2.08
1.94
1.70
1.58
1.51
1.43
1.26
1.12
Average
Aggregate
Pricing
Mortality
(5)
0,52
0.52
O. 49
O, 45
0,64
1.07
1,87
3.03
4.80
7.06
10.53
Underlying
Ultimate
Mortality
[(4)x(5)]
(6)
0.67
0.88
0.96
0.94
1.24
1.82
2.95
4.58
6.86
8.90
11.79
* Our company's substandard ART premiums are calculated by the following formula:
Substandard premium
= P[O.9(r -
1) + 1],
wbere P is the standard ART premium and r is the substandard ratio (e.g., for table 2 substandard mor-
tality, • = 1.5). The values in col. 4 v~re obtained by solving this equation for r.
In Table 3, kt~l+s, the proportion reverting five years after issue, is
calculated assuming that persister mortality is equal to table 4 (200
percent) substandard mortality. The value of k is fairly uniform by age,
indicating that about 70 percent of the in-force would revert under these
assumptions. That is, at the time of reversion the underwriting process
would have to be efficient and precise enough to select the 30 percent
of the total persisters and reverters who will be persisters with an average
mortality equal to table 4. This selection probably would have to be
made knowing that some risks placed in the persister class would lapse
rather than pay the higher ultimate premium. Therefore, the under-
writing target might be to select the, say, 50 percent that average
table 2 substandard mortality.
Other Pricing Assumptions and Profits
Under the approach suggested in this discussion, the lapse assumption
should reflect the expected additional lapses that probably would occur
as insureds lapse their policies rather than accept the ultimate rate. The
expense assumption, as pointed out in the paper, would have to include
the extra selection expenses in the year of reversion. With higher than
normal profit margins built into the product as the authors suggest, the
asset share will be positive at the end of the select period. This would
574 SELECT AND ULTIMATE RENEWABLE TERM
TABLE 3
CALCULATION OF IMPLIED kfzl+s
Aggregate Persister
Reverter
kltT+5
Age
Select Mortality Mortality
{[(2)-- (I)]/
x+5
Mortality
(qP) [~l+5 I(2)- (3)]]
t ,000 qtzl
+4,
[ 2 X (1) ] 1,000qlx+~l
(1) (2) (3) (4)
15
...........
20 ...........
25 ...........
30 ...........
35 ...........
40 ...........
45 ..........
50 ..........
55 ..........
60 ..........
65 ..........
70 ..........
0.52
0.52
O. 49
O. 45
O. 64
1.07
1.87
3.03
4.80
7.06
10.53
16.10
1.04
1.04
0.98
0.90
1.28
2.14
3.74
6.06
9.60
14.12
2l .06
32.20
0.33
0.39
0.32
0.37
O. 46
0.68
1.04
1.47
2.10
3.35
5.68
7.24
O, 73
0.80
0.74
0.85
0.78
O. 73
O. 69
O. 66
O. 64
0,66
0.68
0~65
NoTE.--Persister mortality
(qp),
is assumed to be equal to 2 times
the average
aggre-
gate pric ng mortality, which is assumed to
be equal to q~zl+s, the fifth-year select
pricing
mortality.
assure amortization of initial selection expense before the first reversion.
In this situation, the authors suggest that the extra selection expense
can be equated to the initial selection expense, with the reverters equiva-
lent to new issues and the persisters equivalent to not-takens. They
state that
"an
additional expense need be added in the pricing only if it
is expected that more people will be declined for reversion than would
decide not to take the policy if they were new first-time applicants." It
seems, however, that some additional "expense" has been implicitly in-
cluded in the price of the product in the form of higher profit margins
and the expectation of a positive asset share at the end of the select
period (five years in the example). If persisters are greater in number than
not-takens, even
more
additional expense would need to be incorporated
if it were expected that the reverter class would amortize all the reselec-
tion underwriting expense, including that of the persisters who were
declined for reversion.
Marketability of Select and Ultimate ART
Common sense should indicate that the extra selection expense and
the additional first-year compensation associated with reversion under a
select and ultimate ART product would make it more costly than an
otherwise similar aggregate ART product. When we considered intro-
duction of a select and ultimate ART product as a means of reducing
DISCUSSION 575
our deficiency reserve requirements, we found that we could not com-
pete with our own recently introduced aggregate ART product.
The nonguaranteed nature of the renewal premiums is a significant
problem for select and ultimate ART products. Everyone, no doubt,
thinks he will qualify for reversion; however, the assumptions used in
this discussion indicate that 30 percent will not, and in the paper it was
assumed that 50 percent will not. These nonqualifiers will be expected to
pay the higher ultimate premiums. As each reversion period passes, the
size of the persister class grows. Ten years after issue, there probably will
be more persisters than reverters, assuming that the persisters have not
lapsed. After fifteen years, at least two-thirds will be persisters. This
large group of people, by opting for a select and ultimate product, will
have given up the guaranteed standard renewal premiums they would
otherwise be paying for an aggregate ART product.
The nature of a select and ultimate ART would seem to prohibit sub-
standard issues. If, in order to revert, an insured must be a standard
risk, he probably should be standard at issue also. Would a company
that offered only select and ultimate ART be able to insure a substandard
risk?
Summary
The purpose of this discussion was to point out that another approach
to pricing a select and ultimate ART product would be to choose an
appropriate level for the ultimate-year mortality rates and develop the
reversion rates implied by that level of mortality. The discussion was
meant to imply that this would be a more practical way of approaching
select and ultimate ART product development than the procedure sug-
gested in the paper.
JOHN C. GOULD AND ]AMES R. PORTER:
This is a timely paper, since it addresses very real questions in pricing
a currently popular and competitive product. This discussion addresses
questions raised by the authors' observation that lapse rates had little
effect on persister mortality. For their illustrations, the authors assumed
that the same lapse rates applied to the persisters and the reverters.
Calculations involving decrements of mortality (q~) and withdrawal
(qW) commonly employ one of the following expressions for the per-
sistency rate:
1 -- q7 - qT (1)
or
(1 - q7) (1 -
qT). (2)
576 SELECT AND ULTIMATE RENEWABLE TERM
If the q's are from a double decrement table (deaths and withdrawals)
and if both decrements apply simultaneously and continuously, then
expression (1) is exact. This expression is used in the paper. However, if
the only q's available are from separate mortality and withdrawal tables,
formula (14.38) from Jordan's
Life Contingencies
can be used to compute
the double decrement rates from the known single decrement rates. The
persistency rate, in terms of the single decrement rates, is given by the
expression
(1 q~)(1 - q~) -
,~'~'~
-
~ ~
(3)
1 ~ 1 /m /w
• qt qt
Expression (2) is a closer approximation to this expression than is ex-
pression (1). To illustrate the difference between these expressions, as-
sume a mortality rate of 2 deaths per 1,000 and a 10 percent withdrawal
rate. The resulting values of the three expressions are
(1) 0.8980; (2) 0.8982; (3) 0.898245.
If the exposure to withdrawal is on premium due dates (as when there
are no cash values) and weighted heavily on the anniversary (as for
annual premiums or annual increases in premium), expression (2) is the
best approximation to the persistency rate. Given this approximation
and the assumption of the same withdrawal rates for persisters and
reverters, persister mortality is independent of withdrawal rates:
(qp)t = qtlt_~(1 -- qt-:) -- (qr)t(lr),_~[1 --
(qr)t_~] " (4)
(lp)t_i[1 -- (qp),_,]
Table I of this discussion compares persister mortality rates computed
using the authors' formula with those computed using the formula above
under various withdrawal assumptions. The assumed basic mortality is
from a five-year select table with select rates equal to the following per-
centages of the ultimate rates (see Table 3): 85 percent in the first year,
then 90, 94, 97, and 99 percent. Reversion rates assumed are 50 percent
of in-force at the end of two years, and 30 percent of persisters in force
at the end of four years.
The first column of Table 1 shows persister mortality rates assuming
no lapses. These will also be the mortality rates assuming equal lapse
rates for reverters and persisters and using expression (2) for the per-
sistency rate.
Column 2 of Table 1 shows persister mortality calculated using the
authors' formulas with a flat I0 percent lapse rate. A comparison of
columns 1 and 2 illustrates the very slight effect of the assumed lapses.
DISCUSSION
TABLE 1
COMPUTED PERSISTER MORTALITY RATES (X|,000)
577
Flat 10% Lapses from Lapses from
Attained Age No Lapse Lapse Table 3 Table 3
(1) (z) (3) (~)
30 ..............
31 ...............
32 ...............
33 ...............
34 ...............
35 ...............
36 ...............
37 ...............
38 ...............
39 ...............
1.8275
1. 9800
2•3175
2. 423266
2. 691554
2.714481
2.756132
2. 836050
3.012877
3. 250
1. 8275
1. 9800
2•3175
2. 423274
2.691568
2.714503
2. 756146
2. 836055
3 •012879
3. 250
1 •8275
I. 9800
2.3175
2. 4775
2. 7923
2.7911
2•7918
2. 843824
3 •015653
3. 250
1.8275
1.9800
2.3175
2. 4669
2. 7488
2. 7802
2. 7892
2. 843854
3.015664
3. 250
NoTz.--Column 3 calculated using expression (1) of this discussion; col. 4 calculated using expression (2).
Columns 3 and 4 show the effect of assuming that the lapse rates from
the withdrawal table are combined rates but that the reverters' lapse
rates are significantly lower. (It could be argued that the reverters have
lower lapse rates because they pay lower premiums, or that the persisters
have lower lapse rates because a significant portion have discovered that
they are uninsurable or are rated risks.) Column 3 was computed using
the authors' formulas, while column 4 uses the expressions in this dis-
cussion. (Lapse assumptions used are shown in Table 3.) Persister lapse
rates, shown in Table 2, were computed in a manner analogous to the
method used for the persister mortality rates.
Our conclusions are as follows:
I. When differing lapse rates can be confidently assumed (from experience) for
persisters and reverters, they should be recognized for their effect on both
mortality and persistency. Until then, it is reasonable as well as convenient
TABLE 2
PERSISTER LAPSE RATES (PERCENT), COMPUTED USING LAPSE RATES
IN TABLE 3, AND EXPRESSIONS (1) AND (2) OF THIS DISCUSSION
30.
31.
32.
33.
34.
Attained
Age
Expression
(i)
0.0
25.0
25.0
12. 5345
15.3813
Expression
(2)
0.0
25.0
25.0
12. 5361
15.3843
Attained
Age
35.
36.
37.
38.
39.
Expression
(1)
., 9. 5864
6. 8450
i I 5.o
.i 5.o
• 5.0
Expression
(2)
9. 5890
6.8466
5.0
5.0
5.0
578
SELECT AND ULTIMATE RENEWABLE TERM
TABLE 3
MORTALITY AND LAPSE ASSUMPTIONS USED IN
THE ILLUSTRATIONS
Ultimate
Attained Mortality Aggregate
Age X 1,000 Lapse (%)
(2) (2)
30 ........
31 .....
32 .....
33 .....
34 .....
35 .....
36 .....
37 .....
38 .....
39 .....
2.15
2.20
2.25
2.33
2.40
2.50
2.65
2.80
3.00
3.25
0.0
25.0
15.0
10.0
9.0
7.0
5.5
5.0
5.0
5.0
Reverter at Reverter at
Duration 2 Duration 4
Lapse (%) Lapse (%)
(3) (4)
5.0 ..........
8.0
7.0 3.0
6.0 6.0
5.0 5.0
5.0 5.0
5.0 5,0
5.0 5.0
to compute persister mortality ignoring withdrawals. Given the computed
mortality table, various withdrawal rates can and probably should be tested.
2. The "conservation of total deaths" concept is a little too handy. It would
not be appropriate to adopt it this early as a generally accepted actuarial
assumption like the time-honored concept of uniform distribution of deaths.
In the meantime, this paper defines an important territory of uncertainty
and begins to map it.
COURTLAND C. SMITH:
Messrs. Dukes and MacDonald have presented a timely and interesting
paper. For the rational, informed consumer in an inflationary environ-
ment, the product is a plus. The select and ultimate annual renewable
term (S/U ART) policy gives low-cost insurance. With reversion, the
customer's options are increased. Given continuing competition, costs can
only come down.
The product would seem to represent a positive development for the
rational, informed agent as well. Caught in the squeeze between declining
first-year commissions and rising living costs, the agent is forced to make
more frequent sales or sell ever larger policies to survive. S/U ART, with
its reversion feature, legitimizes frequent resales to existing customers
who remain in good health.
For the rational, knowledgeable life insurance company, S/U ART
represents an opportunity and a problem. The company needs new busi-
ness to survive, and the product is attractive. S/U ART can help attract
new healthy lives, but the company may not prosper as a result. Much
DISCUSSION 579
existing in-force may simply be rewritten. The business written may not
persist long enough to amortize first-year costs. The proportion reverting
may be greater than anticipated, and both reverters and persisters may
then show much higher mortality than was assumed in the original
pricing. Thus, the Dukes-MacDonald S/U ART product seems espe-
cially vulnerable to lapse by healthy lives at the start of the third, fifth,
and sixth durations, and to renewal by lives less healthy than anticipated
at the start of the sixth and later durations.
The solution to the life company's problem lies in the fact that there
are numerous reinsurance compauies in the marketplace that are willing
to compete aggressively for new business. By coinsuring the lapse risk
as well as the mortality risk at favorable allowances, the direct company
can shift the hazards of S/U ART to the reinsurers and remain confi-
dently competitive. I have heard it said that some term policies being
sold today are profitable only because of the reinsurance.
It seems to me that the most refined form of S/U ART policy would
allow reversion every year. To save underwriting expenses, medical
requirements would be reduced each policy year, except perhaps the
fifth, tenth, fifteenth, and so on. As cases reach their first anniversary,
and the insureds are given the option to revert, the healthiest insureds
are likely to submit evidence first, and very little adverse information
is likely to be found. I think it would be very tempting, given these
early results, for the marketing department to propose that further
requests for evidence be waived in the first year in order to reduce both
expenses and lapses! Interestingly, if the coinsurance conditions are
sufficiently competitive, it could pay the actuary to ask his reinsurers
to agree. And it might be difficult for them to refuse!
I have heard the S/U ART policy described as the first life insurance
product in history designed to self-destruct. In the present market, I
suspect that the policy may survive, but some individual companies
may self-destruct instead.
The property-casualty insurance market is based mainly on sales of
annual renewable term policies having yearly reentry provisions. With
inflation in medical costs and property repair charges, claim costs and
coverage limits tend to rise. Premiums tend to exhibit a roller-coaster
pattern. Premiums increase faster than claims when catastrophic experi-
ence or technological innovation drives excess reinsurance capacity out
of the market, but more slowly than claims when a series of profitable
years draws insurance and reinsurance capacity back in. In the capacity-
contraction phase, it is not unusual for companies to self-destruct or
merge.
580 SELECT AND ULTIMATE RENEWABLE TERM
To some observers, the property-casualty roller-coaster cycle lasts an
average of six to seven years. The life insurance industry has all the signs
of moving in the same direction. If so, I wonder how long the life cycle
will be.
(AUTHORS' REVIEW OF
DISCUSSION)
JEFFERÂ¥ DUKES AND ANDREW M. MAC DONALD:
We were somewhat disappointed that this paper did not generate more
written discussion of the merits, viability, and pricing methodology of
S/U ART products, especially since so many companies are issuing or
reinsuring such plans. However, we did receive three such discussions,
and we wish to thank these contributors for taking the time to put their
thoughts in writing.
Before we examine each discussion separately, we would like to ad-
dress one issue that was raised in two responses to our paper, that is,
the issue of assuming different lapse rates for the persisters than for the
reverters. Mr. Bakos argues convincingly that persister lapse rates will
be higher than aggregate ART lapse rates and that reverter lapse rates
will be lower. Messrs. Gould and Porter suggest that differing experiential
lapse rates should be recognized for their effect on mortality; until such
experience is available, they advocate employing a "conservation of total
lapses" principle to develop differing lapse rates for each class. On this
issue, we would like to make the following points:
1. We realize that there is a case for assuming different lapse rates for the
persisters than for the reverters. In the absence of any experience, however, the
introduction of different lapse rates greatly complicates the formulas needed to
calculate persister mortality. For instance, let us assume that lapse rates for
reverters are equal to those for aggregate ART but that lapse rates for per-
sisters are higher than those for aggregate ART. These extra lapses could be
viewed as extra reverters in the context of our generalized formula, which allows
for annual reversions. The mortality rate for the reverting class then would be
a blend of standard mortality for the true reverters and some degree of sub-
standard mortality for the extra persister lapses. The generalized formula
would become
lt~]+*qt~l+t (lp)txl+*(qP)tz1+t + = q*ttzl+~l+t-~(lr)
ttz]+n]+,-, ,
n~l
where qtt,l+~l+t-~ is the blended mortality rate referred to above. The clear
difficulty is in quantifying the degree of the substandard mortality to be sus-
tained by the extra persister lapses. It probably is safe to say that there will
be no extra persister lapses before the first contractually allowed opportunity
to revert; thus, for those years, *
qtttl+-l+t-. ----- qli2l+nl+t-. = qlt+nl+t-n. After
that point, however, there is considerable question as to what will happen. It
DISCUSSION 581
could be argued that all extra persister lapses will occur immediately when
reversion is denied and that no additional lapses will occur after that point.
This would confine the blended mortality problem to one cohort of reverters
but would leave the problem of choosing the blended mortality level. The
problem expands if one assumes that there will be additional persister lapses
in all durations after the first reversion opportunity. Assuming higher persister
lapses at the first reversion opportunity and lower persister lapses afterward
complicates matters further--those lower lapses could be considered as negative
reverters, perhaps in a high-risk class.
In any case, it should be clear that assuming different lapse rates for per-
sisters and reverters poses some serious challenges for the pricing actuary.
2. Mr. Bakos's approach to the above-described complexities is to assume
that mortality levels and persistency levels operate independently of each
other. If we read his comments correctly, he believes that one can set the
persister premium at a level high enough to eliminate deficiency reserves and
not worry about the effect of persistency on the viability of those premiums.
It seems clear to us that setting persister premiums at a table 4 level as he
suggests would expose the company to the same cycle of lapses by the better
risks (table 3 or better), leading to higher sustained mortality, which, in turn,
would lead to losses or higher persister premiums.
3. A proposed alternative to these complicated formulations is the use of a
"conservation-of-total-lapses" principle. Although we had difficulty following
Messrs. Gould and Porter's calculation, it appears that this approach solves
for the persister-class lapse rate by establishing a lapse rate for the reverter
class and assuming that the mortality rate for the two classes is the same (much
as we solved for the persister-class mortality rate by assuming a reverter-class
mortality rate and equal lapse rates for the two classes). This assumption does
not seem appreciably better than our assumption that the lapse rates are the
same. Having to assume that mortality rates are the same for both classes in
order to arrive at this assumption is one flaw. Also, the conservation-of-deaths
principle works because people do not choose to die; so as long as you insure
the same class of risk, total deaths should be the same. The conservation-of-
lapses principle does not work because people can choose to lapse depending on
the premium scale they are paying; thus, total lapses would not necessarily be
the same.
4. In any case, Messrs. Gould and Porter's discussion shows that there ap-
pears to be no substantial difference between persister mortality calculated
using our admittedly convenient lapse assumptions and that calculated using
their approach with separate lapse rates for persisters and reverters. The maxi-
mum differential is roughly 7 deaths per 100,000 and is often much less than
that. This differential seems especially small in light of the approximate nature
of the other assumptions that must be made in pricing this product. These find-
ings corroborate our conclusion that relative lapse rate differentials have only
a minor effect on persister mortality.
582
SELECT AND ULTIMATE RENEWABLE TERM
To a large extent, the second conclusion in the Gould-Porter discussion
is included in our paper. Since lapse rates appear to play a relatively
small part in determining persister mortality, it would be a better use
of time to calculate the effect of different reversion rates. With regard to
the third conclusion, while "conservation of total deaths" may be handy,
it is also entirely reasonable. We do not comprehend how splitting a
group of risks into two subgroups could result in a different number of
deaths for the sum of the two subgroups than for the group as a whole.
It would have been helpful if the contributors had elaborated on this
point.
Mr. Bakos suggests that a primary reason for developing an S/U ART
plan is to reduce deficiency reserves while offering competitive rates.
A plan developed with this objective would resemble a non-guaranteed-
premium aggregate plan if "reversion" underwriting were minimal. Such
a plan really could not have select premiums, since mortality would be
aggregate. We were not aware that lower deficiency reserves were a
major factor in the development of true S/U ART plans--the idea seems
reasonable, but they were not a factor at our company. In fact, at the
time we priced this plan, the method being used to value deficiency
reserves (pre-1976 amendments) produced deficiencies in the early years
of the contract comparable to those for our aggregate plan. If a company
were to develop an S/U ART plan with the hope of getting immediate
surplus relief, it would be disappointed.
Mr. Bakos continues his discussion with the observation that persister
mortality is just as dependent on persister lapse rates as on reversion
rates and that, since neither is easy to predict, one should not try. He
proposes fixing the level of persister mortality at an expected substandard
level and calculating appropriate ultimate (substandard) premium rates.
Using the fixed persister mortality, aggregate mortality, and conserva-
tion of total deaths, one then calculates the theoretical reversion per-
centage and directs the underwriters to underwrite reversions so that
ultimate mortality is as anticipated.
We feel that there are some serious flaws in this approach. For instance,
how much control over reversions can the company really exercise via
its underwriting program? Mr. Bakos plans to keep the premiums for
the persister class in line by restricting the number that can revert, thus
increasing the number of persisters. It is not clear where these extra
persisters are to be obtained. Presumably they would otherwise have
been reverters. If they were standard risks under new-issue underwriting
standards, then the underwriter would either be discriminating unfairly
by letting some standard risks revert and not others, or he would have to
DISCUSSION 583
require that reverters (and new issues?) be superselect. If the latter, then
the standard persisters will obtain another policy elsewhere, thereby in-
creasing the mortality of the remaining persisters and defeating the
objective. The other possibility is that, if 70 percent are allowed to
revert, underwriting on reversion is more lax than at issue, and that
you are merely tightening the underwriting when you increase the size
of the persister group. Even so, these new persisters must be better risks
than the unenlarged group of persisters, and we would think that they
would be less willing to pay the high ultimate rate than the original 30
percent, again defeating the objective. So what to do? Lower the ultimate
rate and start over? It seems at least possible that the end result of a
process like this will be an aggregate plan.
Additionally, one should not be overly preoccupied with the rate of
reversion at the contractually allowed point if insureds can revert de
facto before that point. Those early reversions may be a real source of
loss--so much so that few "persisters" remain by the time the first con-
tractual reversion date arrives.
Also, from a theoretical point of view, it seems dangerous to adopt a
pricing philosophy that involves setting the premiums (i.e., ultimate
persister premiums) and then deriving the experience assumptions (i.e.,
reversion rates) that they will support.
Mr. Bakos's hypothesis that the reverter class eventually might
become superselect while the persisters' mortality remains above the
level of ultimate mortality is conceivable. For example, a group of re-
verting insureds underwritten as standard at several points over the
past few years might be a better class of risk than a group of new issues
likewise underwritten as standard. One reason this might happen is
that the group of reverting insureds would have had more exposure to
the underwriting process than the new issues, thus providing the com-
pany with a correspondingly greater chance to discover underlying
medical problems. It is not clear whether, or to what degree, this would
actually occur. If some assumption could be made as to the improvement
in mortality among the reverting group, the conservation-of-deaths
principle would provide the mortality assumption for the persister
group, which would be higher than ultimate.
In discussing expense considerations, we did not say that persisters
are equivalent to not-takens, as Mr. Bakos has suggested, although that
would be the case if everyone applied for reversion. We did not view the
higher-than-normal profit goal as an extra expense but rather as an
added risk charge for a very risky product.
We agree that the nature of an S/U ART product would seem to pre-
584 SELECT AND ULTIMATE RENEWABLE TERM
clude substandard issues. However, the marketplace dictates otherwise,
and substandard S/U ART products are available in abundance. We
also agree that it is difficult to see how such a product really can be
cheaper in the long run for most insureds.
Mr. Smith succinctly raises the question of the viability of S/U ART
and suggests that reinsurers are doing much to foster its increasing
popularity. He points out the extremely competitive nature of today's
reinsurance market, which means that a writing company usually can
find at least one reinsurer that will offer competitive coinsurance allow-
ances on virtually any product. Not only do marketing pressures force
reinsurers to be superaggressive in pricing, but, as Mr. Smith illustrates
with an essentially true-to-life example, they can be pressured into
accepting questionable underwriting practices on existing plans as well.
Mr. Smith's comparison with property/casualty products is quite apt.
It is interesting to note that these products generally pay a level com-
mission, which may indicate the future direction of the term insurance
market.
There is, perhaps, a place for S/U ART, but, in our opinion, not in the
form addressed in the paper. Reinsurers have used select and ultimate
YRT rates for years--clearly the opportunities for agent and insured
selection are not present there. Another possibility that may have merit
is to charge select and ultimate premiums for the pure insurance com-
ponent of a universal life plan. However, we agree with Mr. Smith and
dozens of other actuaries with whom we have discussed S/U ART that
those companies selling products (be they term or "whole life") with
select premiums may be asking for trouble. Time will tell whether
trouble will respond, but we expect it will. The purpose of our paper was
not to allay the fears of hesitant actuaries about to price this type of
plan but rather to point out the huge uncertainties involved and indicate
a method whereby one could evaluate results under different scenarios.