Abstract
For the theory in line with the actual much more and the actuarial model closes to insurance practice better, this article researches n years’ term life insurance which pays 1 unit at the end of death of the insured person as the object, and researches stochastic interest rate which links the actual situation more closely as the target, then improves the traditional actuarial model to work out result more realistic and makes the maximize approach between the theoretic achievement and the practice circumstance. Firstly, we compute the expect value of present value of payment (i.e. net single premium) under fixed interest rate as the reference group. Subsequently, utilise stochastic interest rate substitute for the fixed interest rate, and sets a random model about interest force by Wiener process, then makes sure the expect value of accumulation function of interest force through the character of distribution of stochastic process, from what we can get the net single premium of this kind of life insurance under stochastic interest rate. Through comparing with the reference group above and computing the final result with example, we can analyze and gain the impact level of the stochastic interest rate affects the net single premium of this kind of life insurance.
Key words: Stochastic interest rate; Term life insurance; Net single premium; Wiener process