This paper deals with asymptotically efficient estimation in exchangeable nonlinear dynamicpanel models with common unobservable factor. These models are especially relevantfor applications to large portfolios of credits, corporate bonds, or life insurance contracts, andare recommended in the...

The recursive prediction and filtering formulas of the Kalman filter are difficult to implementin nonlinear state space models. For Gaussian linear state space models, or for models with qualitativestate variables, the recursive formulas of the filter require the updating of a finite number...

The aim of this paper is to explain why cross-sectional estimated migration correlations displayed in the academic and professional literature can be either not consistent, or inefficient, and to discuss alternative approaches. The analysis relies on a model with stochastic migration in which...

In this paper we explain how to use rating histories provided by the internal scoring systems of banks and by rating agencies in order to predict the future risk of a set of borrowers. The method is developed following the steps suggested by the Basle Committee. To introduce both migration...

The aim of this paper is to extend the results of Jarrow, Yu (2001) onthe spread term structures of corporate bonds. We first consider differentcharacterisations of these term structures, when the available informationcorresponds to the default histories of the firms. The approach is then...

We consider an homogeneous class of assets, whose returns are driven by an unobservablefactor. We derive approximated prediction and pricing formulas for the future factorvalues and their proxies, when the size n of the class is large. Up to order 1=n, these approximationsinvolve solely...

The recursive prediction and filtering formulas of the Kalman filter are difficult to implement in nonlinear state space models. For Gaussian linear state space models, or for models with qualitative state variables, the recursive formulas of the filter require the updating of a finite number of...