A new De Vylder type approximation of the ruin probability in infinite time

In this paper we introduce a generalization of the De Vylder approximation. Our idea is to approximate the ruin probability with the one for a different process with gamma claims, matching first four moments. We compare the two approximations studying mixture of exponentials and lognormal claims. In order to obtain exact values of the ruin probability for the lognormal case we use Pollaczeck-Khinchine formula. We show that the proposed 4-moment gamma De Vylder approximation works even better than the original one.