Risk Modeling


Risk modelling is about modeling and quantification of risk. For the financial industry, the cases of credit-risk quantifying potential losses due, e.g., to bankruptcy of debtors, or market-risks quantifying potential losses due to negative fluctuations of a portfolio's market value are of particular relevance. Operational risk, quantifying potential losses incurred due to failing processes is a relevant issue for any form of organization.

Our approach to risk modelling pays particular attention to systemic risk in complex systems. Issues we have recently looked into are the analysis of operational risks paying particular attention to interdependence of processes, the analysis of credit risks in portfolios containig mutually dependent firms. We have also proposed models explaining the intermittent nature of market dynamis in terms of interacting prices.

Rather spectacular recent examples illustrating our predictions concerning the possibility of first order phase transitions to catastrophic breakdown in systems of interacting processes are the large scale black-outs affecting the north eastern part of the US and parts of Canada in August 2003, and  major black-outs in London, in Denmark and the southern part of Sweden, as well as a country-wide one in Italy in the same month.

A major blackout spreading through parts of Germany, France, Belgium, Austria, Italy and northern Spain on the eve of Nov 4, 2006 might illustrate the salient features of phase-transitions in operational risk perhaps even better: The blackout appears to have been caused by switching off a 380kV power line across the river Ems, so as to allow safe passage of the newly built cruise ship "Norwegian Pearl" to the North Sea. The blackout itself, however, was sparked off only half an hour after the line had been cut, fitting remarkably well to expectations derived from our analysis: cutting the line would have shifted major regions of the grid closer to intrinsic instability so that a normal fluctuation (one that might be expected to occur within the time frame of a few hours, rather than several years) could cause the actual large scale break-down of the grid itself.

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last modified: 01.09.21  rk

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