Using a unique data set on German banks' sector specific loan exposures to the real economy and the corresponding write-offs and write-downs, we examine the impact of loan portfolio sector concentration on credit risk. By controlling for common risk factors, we separate the bank-specific...

Results from portfolio models for credit risk tell us that loan concentration in certain industry sectors can substantially increase the value-at-risk (VaR). The purpose of this paper is to analyze whether a tractable infection modelʺ can provide a meaningful estimate of the impact of...

Regulators in most countries limit the amount of spectrum that a carrier is allowed to obtain as a way of reducing the risk that rival cellular carriers will be unable to obtain the spectrum they need to compete effectively. For similar reasons, regulators may consider how a proposed merger...

This paper develops an empirical procedure for analyzing the impact of model misspecification and calibration errors on measures of portfolio credit risk. When applied to large simulated portfolios with realistic characteristics, this procedure reveals that violations of key assumptions of the...