These notes represent our summary of much of the recent research that
has been done in recent years on approximations and bounds that have
been developed for compound distributions and related quantities which
are of interest in insurance and other areas of application in applied
probability. The basic technique employed in the derivation of many
bounds is induc- tive, an approach that is motivated by arguments used
by Sparre-Andersen (1957) in connection with a renewal risk model in
insurance. This technique is both simple and powerful, and yields quite
general results. The bounds themselves are motivated by the classical
Lundberg exponential bounds which apply to ruin probabilities, and the
connection to compound dis- tributions is through the interpretation of
the ruin probability as the tail probability of a compound geometric
distribution. The initial exponential bounds were given in Willmot and
Lin (1994), followed by the nonexpo- nential generalization in Willmot
(1994). Other related work on approximations for compound distributions
and applications to various problems in insurance in particular and
applied probability in general is also discussed in subsequent chapters.
The results obtained or the arguments employed in these situations are
similar to those for the compound distributions, and thus we felt it
useful to include them in the notes. In many cases we have included
exact results, since these are useful in conjunction with the bounds and
approximations developed.