can a great idea whose day has passed offer a template for
future innovations in actuarial practice?
Al THo Ug H it was published in 1986, the classic Society of Actuaries (SOA) textbook Actuarial Mathematics still devoted a few pages
to a description of traditional commutation columns. But the heyday
for their use was already in eclipse.
With the advent of
personal computers, the
volumes of published commutation columns once so
commonly found on the
reference shelves of actuarial departments are
hardly needed. While
the need for checking
computations hasn’t
disappeared and the
traditional injunction of minding one’s
p’s and q’s readily applies to today’s
actuaries as they
compute reserves
and premiums
directly from the underlying mortality and interest vectors, the days when
actuaries had to match reserves in published
volumes to the penny are nearly gone.
trAditionAL
commutAtion
coLumns
d, n, s, c, m, r
D stands for denominator and n for numerator
in the expression n/D for
an annuity due. S stands
for the sum of the ns;
and C, M, and R are assigned from the letters
immediately preceding D,
n, and S in the alphabet.
from tables to columns
In fact, when commutation columns were
invented, they marked a revolution in ac-
tuarial computing. The computations that
today’s actuaries perform with ease in their
spreadsheets and computer programs were
once long and laborious manual efforts, even
with the aid of John Napier’s marvelous in-
vention of logarithms in 1614.
veCToRSToCk, ShUTTeRSToCk
28 continGencies JUL | AUG. 10
