Extends contagion models to include direct and indirect impacts of defaults on the environment.
problem Capturing the impact of defaults on a broader economy.
method Introduces a new model allowing direct and indirect contagion within and from a default system.
result Shows how defaults within a system can affect the environment and vice versa.
Study connects bank default models using dynamic contagion.
problem Understanding default contagion in heterogeneous interbank systems.
method Proposes a dynamic default contagion model with endogenous early defaults for a finite set of banks, reformulating as a stochastic particle system.
result Existence of clearing systems and continuity of the system response for the mean-field problem.
Mean field game with defaultable agents and systemic risk quantified.
problem Modeling systemic risk in a financial system with defaultable agents.
method Introduced a mean field game with default, provided an explicit solution, and derived an equation for default probability evolution.
result Systemic risk is described by the evolution of default probability.
Model financial default cascades on sparse graphs via hitting times.
problem Capturing systemic risk in large, sparsely-connected financial networks.
method Dynamic particle systems with hitting times and convergence theory.
result Characterization of default time distribution in tree-like networks.
We study large deviations and rare default clustering events in a dynamic large heterogeneous portfolio of interconnected components. Defaults come as Poisson events and the default intensities of the different components in the system interact through the empirical default rate and via systematic effects that are comm…
Study on sequential defaulting in financial networks, analyzing stability and optimal timing.
problem Understanding which banks default and how much they can fulfill in a sequential financial network.
method Sequential model of financial networks, analyzing stability and optimal timing of defaults.
result Stabilization time can heavily depend on the ordering of announcements, and finding the best time for default is NP-hard.
Modeling default contagion and systemic risk using a balls-and-bins approach.
problem Understanding and quantifying systemic risk in financial networks.
method Tractable model, balls-and-bins representation, type space classification, limit theorems.
result Asymptotic Gaussian fluctuations in the final size of default cascades.
Paper proposes a framework for precise daily default risk prediction of Chinese credit bonds.
problem Inadequate and inaccurate bond information disclosure creates risk of default for investors.
method Framework includes summarizing factors impacting defaults, constructing a risk index system, and using ConvLSTM neural network for prediction.
result The model provides more responsive and accurate daily default risk predictions than authoritative ratings.
Study on default clustering in large networks using graph theory.
problem Understanding the impact of defaults in large interconnected systems.
method Law of large numbers applied to graph dynamics, singular value decomposition of adjacency matrix.
result Identification of components with highest contagion impact using eigenvalues.
We propose an interacting particle system to model the evolution of a system of banks with mutual exposures. In this model, a bank defaults when its normalized asset value hits a lower threshold, and its default causes instantaneous losses to other banks, possibly triggering a cascade of defaults. The strength of this …
Paper introduces new risk measures for default risk and model uncertainty.
problem Model uncertainty and default risk in rating systems.
method Introduces default risk measures and discusses their properties and impacts.
result Different default risk measures and margins of conservatism affect risk-weighted assets.
An insurer optimizes investment and risk control with default contagion and regime-switching.
problem Maximizing expected utility of terminal wealth in a risky market with default events.
method Develops a truncation technique to analyze the recursive HJB system and proves the existence and uniqueness of solutions.
result Characterizes optimal trading strategy and risk control for the insurer.
As it is known in the finance risk and macroeconomics literature, risk-sharing in large portfolios may increase the probability of creation of default clusters and of systemic risk. We review recent developments on mathematical and computational tools for the quantification of such phenomena. Limiting analysis such as …
We develop a structural default model for interconnected financial institutions in a probabilistic framework. For all possible network structures we characterize the joint default distribution of the system using Bayesian network methodologies. Particular emphasis is given to the treatment and consequences of cyclic fi…
Statistical test verifies long-term rating system calibration with overlapping time windows.
problem Verifying supervisory requirements for overlapping time windows in rating systems.
method Analyzes long-run default rate distribution and correlation effects; presents conservative calibration test methods.
result Developed a test for individual and portfolio levels that can handle unknown variance.
Optimal credit and consumption strategies in a switching market with default contagion.
problem Optimal portfolio and consumption decisions in a credit market with default contagion.
method Cobb-Douglas utility, recursive ODE system, backward solution from all-default state.
result Existence and uniqueness of optimal feedback controls, verification theorem.
Modeling systemic risk with contagion effects in financial systems.
problem Capturing systemic risk and contagion effects in large financial systems.
method Dynamic mean field model derived from interacting diffusions with an absorbing boundary.
result The SPDE model exhibits periods of significant default clustering due to contagion.
Model connects financial contagion models to mean field analysis.
problem Systemic risk in financial networks.
method Combines Eisenberg-Noe and mean field models.
result Mean field limit derived from finite bank system.
We consider a multivariate default system where random environmental information is available. We study the dynamics of the system in a general setting and adopt the point of view of change of probability measures. We also make a link with the density approach in the credit risk modelling. In the particular case where …
The article constructs a forward utility for markets with multiple default risks.
problem Characterizing forward performance processes in a market with multiple default risks.
method Using Jacod-Pham decomposition and recursive BSDEs, the article constructs a forward utility and proves its existence and uniqueness.
result The article identifies the risk-sensitive long-run growth rate of the optimal wealth process in a stochastic factor model with ergodic dynamics.
The question of how to stabilize financial systems has attracted considerable attention since the global financial crisis of 2007-2009. Recently, Beale et al. ("Individual versus systemic risk and the regulator's dilemma", Proc Natl Acad Sci USA 108: 12647-12652, 2011) demonstrated that higher portfolio diversity among…
It had been believed in the conventional practice that the risk of a bank going bankrupt is lessened in a straightforward manner by transferring the risk of loan defaults. But the failure of American International Group in 2008 posed a more complex aspect of financial contagion. This study presents an extension of the …
We develop a finite horizon continuous time market model, where risk averse investors maximize utility from terminal wealth by dynamically investing in a risk-free money market account, a stock written on a default-free dividend process, and a defaultable bond, whose prices are determined via equilibrium. We analyze fi…
The paper analyzes financial networks with default charges and defines a model using fixpoint problems.
problem Modeling systemic risk in interbank networks with crossholdings and default charges.
method Mixed integer-linear programming and Gaussian elimination algorithm for computing clearing pairs.
result Developed methods to compute maximal and minimal clearing pairs.
The scope of financial systemic risk research encompasses a wide range of interbank channels and effects, including asset correlation shocks, default contagion, illiquidity contagion, and asset fire sales. This paper introduces a financial network model that combines the default and liquidity stress mechanisms into a "…
We prove a law of large numbers for the loss from default and use it for approximating the distribution of the loss from default in large, potentially heterogenous portfolios. The density of the limiting measure is shown to solve a non-linear SPDE, and the moments of the limiting measure are shown to satisfy an infinit…
iConViz helps banks manage default contagion risk in networked loans.
problem Managing default contagion risk in networked loans during economic downturns.
method Developed iConViz, an interactive tool, and a novel metric (contagion effect) to quantify and analyze the risk.
result iConViz facilitates closed-loop analysis and helps avoid ad hoc methods.
Study predicts firm defaults using machine learning on Italian credit data.
problem Predicting firm defaults to inform bank lending policies.
method Used large granular credit data from Italian Central Credit Register, combined with public balance sheet data, and applied ensemble techniques and random forest models.
result Ensemble techniques and random forest provide the best results for predicting firm defaults.
This paper studies financial network default ambiguity and solution selection.
problem Determining the best solution to financial network default ambiguity.
method Analysis of solution space properties and NP-hardness of approximation.
result Hardness of finding optimal solutions for various objective functions.
Investment strategy optimized for markets and credit risks.
problem Optimal investment/consumption problem in models with market and credit risk dependencies.
method Martingale approach and analysis of nonlinear Hamilton-Jacobi-Bellman equations transformed into semi-linear PDEs.
result Explicit representations for optimal strategy, consumption path, and wealth process.
We propose a model for the credit and liquidity risks faced by clearing members of Central Counterparty Clearing houses (CCPs). This model aims to capture the features of: gap risk; feedback between clearing member default, market volatility and margining requirements; the different risks faced by various types of mark…
Paper uses interbank contagion to predict U.S. bank defaults, finding it highly explanatory.
problem Predicting U.S. bank defaults using interbank contagion.
method Regression and neural network models were used to analyze U.S. commercial bank data.
result Interbank contagion is highly explanatory in default prediction, often outperforming established metrics.
The aim of this paper is to quantify and manage systemic risk caused by default contagion in the interbank market. We model the market as a random directed network, where the vertices represent financial institutions and the weighted edges monetary exposures between them. Our model captures the strong degree of heterog…
A new method estimates corporate bond defaults in financial networks efficiently.
problem Challenges in valuing corporate bonds in interconnected financial systems.
method Bi-Level Importance Sampling with Splitting
result The method efficiently estimates rare default events in financial networks.
We apply multiple testing procedures to the validation of estimated default probabilities in credit rating systems. The goal is to identify rating classes for which the probability of default is estimated inaccurately, while still maintaining a predefined level of committing type I errors as measured by the familywise …
The paper examines clearing payments in financial networks to prevent cascaded defaults.
problem Cascaded defaults in financial networks under the proportionality rule.
method Analysis of clearing model under pro-rated payments, derivation of necessary and sufficient conditions for clearing payments, convex optimization problems for computation.
result Clearing payments can be computed by solving convex optimization problems, reducing overall system loss by lifting the proportionality rule.
Model financial contagion with dynamic interbank liabilities.
problem Model financial contagion with time dynamics of interbank liabilities.
method Generalized Eisenberg-Noe model with time dynamics, separating cash and capital accounts.
result Distinguish between delinquency and default, insolvency and illiquidity.
The consultative papers for the Basel II Accord require rating systems to provide a ranking of obligors in the sense that the rating categories indicate the creditworthiness in terms of default probabilities. As a consequence, the default probabilities ought to present a monotonous function of the ordered rating catego…
This paper develops a structural credit risk model to characterize the difference between the economic and recorded default times for a firm. Recorded default occurs when default is recorded in the legal system. The economic default time is the last time when the firm is able to pay off its debt prior to the legal defa…
Paper studies systemic robustness in financial networks using particle systems.
problem Budget control and default risk in regional financial networks.
method Mean-field particle system approach, McKean-Vlasov equations, asymptotic analysis.
result Systemic robustness measured by the proportion of surviving entities in large particle systems.
Optimal dividend strategy for insurance group with contagious default risk.
problem Optimal dividend strategy for a multi-line insurance group with default contagion.
method Analysis of recursive system of Hamilton-Jacobi-Bellman variational inequalities (HJBVIs).
result Optimal dividend strategy is still of the barrier type, and optimal barrier is modulated by default state.
The study develops a machine learning system for credit scoring and default prediction.
problem Developing a robust credit rating and default prediction system.
method Combines NLP, AE, GBM, DE, and SHAP/LIME for model interpretability.
result Obtained excellent out-of-sample performance in credit rating and default prediction.
Diversification increases systemic risk, contrary to belief.
problem Systemic risk due to diversification at banks.
method Examined diversification's impact on joint default probability and systemic risk using VaR.
result Diversification reduces individual and systemic risk, contrary to common belief.
Study optimal portfolio allocation in credit markets with default contagion.
problem Risk-sensitive portfolio optimization in a regime-switching credit market with default contagion.
method Investigate recursive infinite-dimensional nonlinear dynamical programming equations (DPEs) and develop a verification theorem for optimal feedback strategies.
result Established existence and uniqueness of classical solutions to the recursive DPEs and constructed approximating problems to converge to the original system.
Model predicts default risk based on company's financial forecasts and credit conditions.
problem Estimating the risk of a company defaulting on its financial obligations.
method Developed an equilibrium model linking interest rates to corporate performance and credit supply.
result Estimates idiosyncratic default risk and provides forward-looking probability of default (PD).
Networked-guarantee loans may cause the systemic risk related concern of the government and banks in China. The prediction of default of enterprise loans is a typical extremely imbalanced prediction problem, and the networked-guarantee make this problem more difficult to solve. Since the guaranteed loan is a debt oblig…
The paper calculates the likelihood of a financial market failure involving multiple major banks.
problem Estimating the probability of a market failure involving multiple globally important banks.
method Multivariate Cox process across G-SIBs, deriving various theorems on market failure probabilities.
result The probability of a market failure increases with the number of G-SIBs and is inevitable if there are too many.
Central bank optimizes bailout cash injection to limit defaults.
problem Optimizing cash injection to limit defaults in a system of mutual obligations.
method Proved convergence and solved a drift controlled Stefan problem using mean field control and policy gradient methods.
result Optimal strategies involve subsidizing banks with equity values in a time-dependent region.