A Survival Model Approach to Non-Life Run-off Triangle Estimation

Motivation: Most standard loss reserving techniques do not explicitly consider the rate at which claims will close, or the expected amount of time that a claim will remain open. Consideration of the time until closure allows one to calculate the amount of time until a block of claims will run-off. Further, it allows one to take explicit assumptions with regard to interest and inflation into account.

Method: By observing the closure rates for claims by age, a survival function is produced. This function can be used to determine the future lifetime of a claim at any age and the number of claims remaining open at any time.

Results: The method applied to a set of sample data generates a complete picture of the future pattern of claim disposal.

Conclusions: The method presented here grounds the projection of future claim run-off in theory common to life actuaries and opens up the life toolset to the analysis of non-life data.

Keywords: Reserving; Survival models.