Università della Svizzera italiana

Robust subsampling

Camponovo, Lorenzo ; Scaillet, Olivier ; Trojani, Fabio

In: Journal of econometrics, 2012, vol. 167, no. 1, p. 197-210

We characterize the robustness of subsampling procedures by deriving a formula for the breakdown point of subsampling quantiles. This breakdown point can be very low for moderate subsampling block sizes, which implies the fragility of subsampling procedures, even when they are applied to robust statistics. This instability arises also for data driven block size selection procedures minimizing ...

Université de Fribourg

Robustness analysis and convergence of empirical finite-time ruin probabilities and estimation risk solvency margin

Loisel, Stéphane ; Mazza, Christian ; Rullière, Didier

In: Insurance: Mathematics and Economics, 2008, vol. 42, no. 2, p. 746-762

We consider the classical risk model and carry out a sensitivity and robustness analysis of finite-time ruin probabilities. We provide algorithms to compute the related influence functions. We also prove the weak convergence of a sequence of empirical finite-time ruin probabilities starting from zero initial reserve toward a Gaussian random variable. We define the concepts of reliable finite-time...

Università della Svizzera italiana

Variable selection for marginal longitudinal generalized linear models

Cantoni, Eva ; Mills-Flemming, Joanna ; Ronchetti, Elvezio

In: Biometrics, 2005, vol. 61, no. 2, p. 507-514

Variable selection is an essential part of any statistical analysis and yet has been somewhat neglected in the context of longitudinal data analysis. In this paper we propose a generalized version of Mallows's Cp (GCp) suitable for use with both parametric and nonparametric models. GCp provides an estimate of a measure of model's adequacy for prediction. We examine its performance with popular...