This paper presents a duration dependent model for analyzing the evolution of credit ratings. It considers the backward recurrence process to tackle the time of permanence problem in the rating classes. In this way it is possible to manage the duration effects, which represent one of the most...

In this paper, we present a stochastic model for disability insurance contracts. The model is based on a discrete time non-homogeneous semi-Markov process (DTNHSMP) to which the backward recurrence time process is introduced. This permits a more exhaustive study of disability evolution and a...

In this paper we use the index we call Population Dynamic Theil's Entropy to analyze as the income inequality varies on time. The index may consider both the inequality among the classes in which we assign the individuals and the inequality within each class. This inequality measure working in a...

In this paper we propose a stochastic model to analyze the time evolution of inequality within an economic system. The classical inequality indices (Herfindahl-Hirschman, Gini and Theil’s entropy) are thereby turned into a dynamic form. We show, by using a simulative approach, how it is...

This article presents a semi-Markov process based approach to optimally select a portfolio consisting of credit risky bonds. The criteria to optimize the credit portfolio is based on lÉ-norm risk measure and the proposed optimization model is formulated as a linear programming problem. The...

This article presents a semi-Markov process based approach to optimally select a portfolio consisting of credit risky bonds. The criteria to optimize the credit portfolio is based on l∞-norm risk measure and the proposed optimization model is formulated as a linear programming problem. The...

We consider the problem of constructing an appropriate multivariate model for the study of the counterparty credit risk in credit rating migration problem. For this financial problem different multivariate Markov chain models were proposed. However the markovian assumption may be inappropriate...

In this paper we propose a semi-Markov modulated model of interest rates. We assume that the switching process is a semi-Markov process with finite state space E and the modulated process is a diffusive process. We derive recursive equations for the higher order moments of the discount factor...

In this paper we propose a modification of the Dynamic Theil's Entropy that considers the inequality in the whole population. We decompose it into three addends and we show how to compute them within a Markov model of income evolution. In this way the income inequality can be measured in the...