The authors suggest a new method to determinate the limits of the three basic income groups. The Lorenz curve is split of three parts. The middle part corresponds to the middle stratum of incomes. The projections of this part on both axes are equal segments. The empirical Lorenz curve is...

An improved version of a ruin probability formula due to Ignatov and Kaishev [Scand. Actu. J. 1 (2000) 46], allowing for the exact evaluation of the finite-time survival probability for discrete, dependent, individual claims, Poisson claim arrivals and arbitrary, increasing premium income...