The variability of chain ladder
reserve estimates is quantified
without assuming any specific claims amount distribution
function.
This is done by establishing a formula for the so-
called standard error which is an estimate for the standard
deviation of the outstanding claims reserve. The information
necessary for this purpose is extracted only from the usual
chain ladder formulae.
With the standard error as decisive tool
it is shown how a confidence interval for the outstanding claims
reserve and for the ultimate claims amount can
be constructed.
Moreover,
the analysis of the information extracted and of its
implications shows when it is appropriate to apply the chain
ladder method and when not.