TY - JOUR AU - Kasozi, Juma AU - Paulsen, Jostein PY - 2005 TI - Numerical Ultimate Ruin Probabilities under Interest Force JF - Journal of Mathematics and Statistics VL - 1 IS - 3 DO - 10.3844/jmssp.2005.246.251 UR - https://thescipub.com/abstract/jmssp.2005.246.251 AB - This work addresses the issue of ruin of an insurer whose portfolio is exposed to insurance risk arising from the classical surplus process. Availability of a positive interest rate in the financial world forces the insurer to invest into a risk free asset. We derive a linear Volterra integral equation of the second kind and apply an order four Block-by-block method in conjuction with the Simpson rule to solve the Volterra equation for ultimate ruin. This probability is arrived at by taking a linear combination of some two solutions to the Volterra integral equation. The several numerical examples given show that our results are excellent and reliable.