Tid: 19 december 2013 kl 15.15-17.00.Seminarierummet 3721, Institutionen för matematik, KTH, Lindstedts vägen 25, plan 7. Karta!
Föredragshållare: Björn Löfdahl Grelsson, KTH
Titel: Licentiat seminarium: Stochastic modelling in disability insurance
Diskutant: Mogens Steffensen, University of Copenhagen
Abstract: This thesis consists of two papers related to the stochastic modelling of disability insurance. In the first paper, we propose a stochastic semi-Markovian framework for disability modelling in a multi-period discrete-time setting. The logistic transforms of disability inception and recovery probabilities are modelled by means of stochastic risk factors and basis functions, using counting processes and generalized linear models. The model for disability inception also takes IBNR claims into consideration. We fit various versions of the models into Swedish disability claims data. In the second paper, we consider a large, homogeneous portfolio of life or disability annuity policies. The policies are assumed to be independent conditional on an external stochastic process representing the economic environment. Using a conditional law of large numbers, we establish the connection between risk aggregation and claims reserving for large portfolios. Further, we derive a partial differential equation for moments of present values. Moreover, we show how statistical multi-factor intensity models can be approximated by one-factor models, which allows for solving the PDEs very efficiently. Finally, we give a numerical example where moments of present values of disability annuities are computed using finite difference methods.
|Sidansvarig: Filip Lindskog