Quantitative analysis
Pitfalls and alternatives
Correlation
The road to partition
Applying the ensemble approach developed in these pages last month, Kevin Thompson and Roland Ordovas calculate risk contributions and show how to measure higher-order default dependence using the method of partitions. The results provide tools allowing…
Applying modern portfolio theory to optimal gas purchasing
Yijun Du and Xiaorui Hu present a general framework for applying modern portfolio theory to optimal natural gas procurements. They show that successful natural gas procurement involves determining the optimal allocation between fixed-price and floating…
A better approach to operational risk aggregation
Professor Carol Alexander proposes an aggregation methodology that takes account of dependencies between op risk losses that have some common risk drivers.
Credit ensemble
Kevin Thompson and Roland Ordovas address the question of how individual counterparties contribute to the total credit risk of a portfolio. They provide an analytic method, new to credit modelling, to estimate all joint default statistics conditional…
Exceptional operational risks: Three myths debunked
Are there common features among exceptional operational risks beyond their defining characteristics of rarity and severe consequences?
Enhancing CreditRisk+
Of the various analytical approaches to credit portfolio modelling, CreditRisk+ has become the most popular due to its tractability. However, the model suffers from the restrictive assumption of sector independence. Moreover, the recursion relation for…
Credit ensembles
Kevin Thompson and Roland Ordovas address the question of how individual counterparties contribute to the total credit risk of a portfolio. They provide an analytic method, new to credit modelling, to estimate all joint default statistics conditional…
Project risk: improving Monte Carlo value-at-risk
Cashflows from projects and other structured deals can be as complicated as we are willing to allow, but the complexities of Monte Carlo project modelling need not complicate value-at-risk calculation. Here, Andrew Klinger imports least-squares valuation…
Quantifying the op risk in investment fund valuation
Fund management is often forgotten in the wider push towards quantitative operational risk management. Here, François Longin and Gautier Martin take a closer look at the operational risk that accompanies fund valuation.
Contributions to credit risk
Optimisation of credit portfolios requires that risk contributions be quantified. However, there has been disagreement over which of three popular tail risk measures should be used. Here, Alexandre Kurth and Dirk Tasche offer a way forward, showing how…
Advancing op risk management using Japanese banking experience
Junji Hiwatashi and Hiroshi Ashida of the Bank of Japan outline a practical framework for operational risk management, derived from research and experiences in Japan's financial community.
Contributions to credit risk
Optimisation of credit portfolios requires that risk contributions be quantified. However, there has been disagreement over which of three popular tail risk measures should be used. Here, Alexandre Kurth and Dirk Tasche offer a way forward, showing how…
Random tranches
How should economic or regulatory capital be allocated to tranches of securitisations? The standard Basel conditional dependence calculations are complicated in this case by non-linearity effects and complex deal dependence. Here, Michael Gordy and David…
Capturing the smile
Since the discovery that traditional calibration methods fail to capture the dynamics of the smile, new approaches based on mixtures or ensembles of models have been developed. Simon Johnson and Han Lee present a variant of this approach that can be used…
Asian basket spreads and other exotic averaging options
Giuseppe Castellacci and Michael Siclari of OpenLink introduce a class of exotic options that simultaneously generalises both Asian and basket options. They develop approximate analytic models for real-time pricing of complex instruments that average…
Risk management based on stochastic volatility
Risk management approaches that do not incorporate randomly changing volatility tend to under- or overestimate the risk, depending on current market conditions. We show how some popular stochastic volatility models in combination with the hyperbolic…
ORIAG paper published on FSA website
The Operational Risk Implementation Advisory Group (ORIAG), which is chaired by the UK's Financial Services Authority (FSA), has posted its working paper, "Implementation of the Capital Accord for Operational Risk" on its website.
How to avoid overestimating capital charges for op risk
Pooling internal and external data is a central issue to estimating capital charges for operational risk. Here, Nicolas Baud, Antoine Frachot and Thierry Roncalli of Crédit Lyonnais discuss the methodology they have developed.
What causes crashes?
Are large market events caused by easily identifiable exogenous shocks such as major newsevents, or can they occur endogenously, without apparent external cause, as an inherent propertyof the market itself? Here, Didier Sornette, Yannick Malevergne and…
From horses to hedging
Financial derivatives rely on liquid underlying markets to work properly, but what happenswhen such underlying markets do not exist, as is the case for indexes such as GDP orunemployment? Here, Ken Baron and Jeffrey Lange suggest a parimutuel auction…
Extreme forex moves
What is the appropriate statistical description of tail risk in a market portfolio? In the context offoreign exchange, Peter Blum and Michel Dacorogna address this problem using extreme valuetheory. Using 20 years of data, they estimate parameters for an…
A decision model for selling park and loan services
The park and loan model is useful for gas storages and pipelines. The concept can be applied to many ‘when to sell’-type decisions. Here, Huagang ‘Hugh’ Li considers selling park and loan services as a financial and statistical decision on revenue and…
Testing rating accuracy
As Basel II approaches the implementation stage, regulators have identified internal ratings validation as a key challenge for banks using this approach. Here, Bernd Engelmann, Evelyn Hayden and Dirk Tasche build upon previous research showing how to use…