2008/06/20 by Paolo Dai Pra, Pra, Paolo Dai, Marco Tolotti +1
Economics, Econometrics and Finance · Mathematics · #60K35 #91B70 #Banking stability, regulation, efficiency #Credit Risk and Financial Regulations #FOS: Economics and business #FOS: Mathematics #Probability (math.PR) #Risk Management (q-fin.RM) #Stochastic processes and financial applications #math.PR #msc:60K35 #msc:91B70 #q-fin.RM
paper · pdf · doi:10.48550/arxiv.0806.3399
35 pages, 3 figures
arxiv created 2008/06/20 · openalex publication_date 2008/06/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the impact of contagion in a network of firms facing credit risk. We describe an intensity based model where the homogeneity assumption is broken by introducing a random environment that makes it possible to take into account the idiosyncratic characteristics of the firms. We shall see that our model goes behind the identification of groups of firms that can be considered basically exchangeable. Despite this heterogeneity assumption our model has the advantage of being totally tractable. The aim is to quantify the losses that a bank may suffer in a large credit portfolio. Relying on a large deviation principle on the trajectory space of the process, we state a suitable law of large number and a central limit theorem useful to study large portfolio losses. Simulation results are provided as well as applications to portfolio loss distribution analysis.