
Understanding and managing model risk : a practical guide for quants, traders and validators
Title:
Understanding and managing model risk : a practical guide for quants, traders and validators
Author:
Morini, Massimo.
ISBN:
9780470977613
Personal Author:
Edition:
1st ed.
Publication Information:
Chichester, West Sussex : Wiley, 2011.
Physical Description:
xx, 428 p. : ill. ; 25 cm.
Series:
Wiley finance series
General Note:
Formerly CIP.
Contents:
Machine generated contents note: pt. I Theory and Practice of Model Risk Management -- 1.Understanding Model Risk -- 1.1.What Is Model Risk? -- 1.1.1.The Value Approach -- 1.1.2.The Price Approach -- 1.1.3.A Quant Story of the Crisis -- 1.1.4.A Synthetic View on Model Risk -- 1.2.Foundations of Modelling and the Reality of Markets -- 1.2.1.The Classic Framework -- 1.2.2.Uncertainty and Illiquidity -- 1.3.Accounting for Modellers -- 1.3.1.Fair Value -- 1.3.2.The Liquidity Bubble and the Accountancy Boards -- 1.3.3.Level 1, 2, 3... go? -- 1.3.4.The Hidden Model Assumptions in `vanilla' Derivatives -- 1.4.What Regulators Said After the Crisis -- 1.4.1.Basel New Principles: The Management Process -- 1.4.2.Basel New Principles: The Model, The Market and The Product -- 1.4.3.Basel New Principles: Operative Recommendations -- 1.5.Model Validation and Risk Management: Practical Steps -- 1.5.1.A Scheme for Model Validation -- 1.5.2.Special Points in Model Risk Management --
Contents note continued: 1.5.3.The Importance of Understanding Models -- 2.Model Validation and Model Comparison: Case Studies -- 2.1.The Practical Steps of Model Comparison -- 2.2.First Example: The Models -- 2.2.1.The Credit Default Swap -- 2.2.2.Structural First-Passage Models -- 2.2.3.Reduced-Form Intensity Models -- 2.2.4.Structural vs Intensity: Information -- 2.3.First Example: The Payoff. Gap Risk in a Leveraged Note -- 2.4.The Initial Assessment -- 2.4.1.First Test: Calibration to Liquid Relevant Products -- 2.4.2.Second Test: a Minimum Level of Realism -- 2.5.The Core Risk in the Product -- 2.5.1.Structural Models: Negligible Gap Risk -- 2.5.2.Reduced-Form Models: Maximum Gap Risk -- 2.6.A Deeper Analysis: Market Consensus and Historical Evidence -- 2.6.1.What to Add to the Calibration Set -- 2.6.2.Performing Market Intelligence -- 2.6.3.The Lion and the Turtle. Incompleteness in Practice -- 2.6.4.Reality Check: Historical Evidence and Lack of it --
Contents note continued: 2.7.Building a Parametric Family of Models -- 2.7.1.Understanding Model Implications -- 2.8.Managing Model Uncertainty: Reserves, Limits, Revisions -- 2.9.Model Comparison: Examples from Equity and Rates -- 2.9.1.Comparing Local and Stochastic Volatility Models in Pricing Equity Compound and Barrier Options -- 2.9.2.Comparing Short Rate and Market Models in Pricing Interest Rate Bermud an Options -- 3.Stress Testing and the Mistakes of the Crisis -- 3.1.Learning Stress Test from the Crisis -- 3.1.1.The Meaning of Stress Testing -- 3.1.2.Portfolio Stress Testing -- 3.1.3.Model Stress Testing -- 3.2.The Credit Market and the `Formula that Killed Wall Street' -- 3.2.1.The CDO Payoff -- 3.2.2.The Copula -- 3.2.3.Applying the Copula to CDOs -- 3.2.4.The Market Quotation Standard -- 3.3.Portfolio Stress Testing and the Correlation Mistake -- 3.3.1.From Flat Correlation Towards a Realistic Approach --
Contents note continued: 3.3.2.A Correlation Parameterization to Stress the Market Skew -- 3.4.Payoff Stress and the Liquidity Mistake -- 3.4.1.Detecting the Problem: Losses Concentrated in Time -- 3.4.2.The Problem in Practice -- 3.4.3.A Solution. From Copulas to Real Models -- 3.4.4.Conclusions -- 3.5.Testing with Historical Scenarios and the Concentration Mistake -- 3.5.1.The Mapping Methods for Bespoke Portfolios -- 3.5.2.The Lehman Test -- 3.5.3.Historical Scenarios to Test Mapping Methods -- 3.5.4.The Limits of Mapping and the Management of Model Risk -- 3.5.5.Conclusions -- 4.Preparing for Model Change, Rates and Funding in the New Era -- 4.1.Explaining the Puzzle in the Interest Rates Market and Models -- 4.1.1.The Death of a Market Model: 9 August 2007 -- 4.1.2.Finding the New Market Model -- 4.1.3.The Classic Risk-free Market Model -- 4.1.4.A Market Model with Stable Default Risk -- 4.1.5.A Market with Volatile Credit Risk -- 4.1.6.Conclusions --
Contents note continued: 4.2.Rethinking the Value of Money: The Effect of Liquidity in Pricing -- 4.2.1.The Setting -- 4.2.2.Standard DVA: Is Something Missing? -- 4.2.3.Standard DVA plus Liquidity: Is Something Duplicated? -- 4.2.4.Solving the Puzzle -- 4.2.5.Risky Funding for the Borrower -- 4.2.6.Risky Funding for the Lender and the Conditions for Market Agreement -- 4.2.7.Positive Recovery Extension -- 4.2.8.Two Ways of Looking at the Problem: Default Risk or Funding Benefit? The Accountant vs the Salesman -- 4.2.9.Which Direction for Future Pricing? -- pt. II Snakes in the Grass: Where Model Risk Hides -- 5.Hedging -- 5.1.Model Risk and Hedging -- 5.2.Hedging and Model Validation: What is Explained by P&L Explain? -- 5.2.1.The Sceptical View -- 5.2.2.The Fundamentalist View and Black and Scholes -- 5.2.3.Back to Reality -- 5.2.4.Remarks: Recalibration, Hedges and Model Instability -- 5.2.5.Conclusions: from Black and Scholes to Real Hedging --
Contents note continued: 5.3.From Theory to Practice: Real Hedging -- 5.3.1.Stochastic Volatility Models: SABR -- 5.3.2.Test Hedging Behaviour Leaving Nothing Out -- 5.3.3.Real Hedging for Local Volatility Models -- 5.3.4.Conclusions: the Reality of Hedging Strategies -- 6.Approximations -- 6.1.Validate and Monitor the Risk of Approximations -- 6.2.The Swaption Approximation in the Libor Market Model -- 6.2.1.The Three Technical Problems in Interest Rate Modelling -- 6.2.2.The Libor Market Model and the Swaption Market -- 6.2.3.Pricing Swaptions -- 6.2.4.Understanding and Deriving the Approximation -- 6.2.5.Testing the Approximation -- 6.3.Approximations for CMS and the Shape of the Term Structure -- 6.3.1.The CMS Payoff -- 6.3.2.Understanding Convexity Adjustments -- 6.3.3.The Market Approximation for Convexity Adjustments -- 6.3.4.A General LMM Approximation -- 6.3.5.Comparing and Testing the Approximations -- 6.4.Testing Approximations Against Exact. Dupire's Idea --
Contents note continued: 6.4.1.Perfect Positive Correlation -- 6.4.2.Perfect Negative Correlation -- 6.5.Exercises on Risk in Computational Methods -- 6.5.1.Approximation -- 6.5.2.Integration -- 6.5.3.Monte Carlo -- 7.Extrapolations -- 7.1.Using the Market to Complete Information: Asymptotic Smile -- 7.1.1.The Indetermination in the Asymptotic Smile -- 7.1.2.Pricing CMS with a Smile: Extrapolating to Infinity -- 7.1.3.Using CMS Information to Transform Extrapolation into Interpolation and Fix the Indetermination -- 7.2.Using Mathematics to Complete Information: Correlation Skew -- 7.2.1.The Expected Tranched Loss -- 7.2.2.Properties for Interpolation -- 7.2.3.Properties for Turning Extrapolation into Interpolation -- 8.Correlations -- 8.1.The Technical Difficulties in Computing Correlations -- 8.1.1.Correlations in Interest Rate Modelling -- 8.1.2.Cross-currency Correlations -- 8.1.3.Stochastic Volatility Correlations -- 8.2.Fundamental Errors in Modelling Correlations --
Contents note continued: 8.2.1.The Zero-correlation Error -- 8.2.2.The 1-Correlation Error -- 9.Calibration -- 9.1.Calibrating to Caps/Swaptions and Pricing Bermudans -- 9.1.1.Calibrating Caplets -- 9.1.2.Understanding the Term Structure of Volatility -- 9.1.3.Different Parameterizations -- 9.1.4.The Evolution of the Term Structure of Volatility -- 9.1.5.The Effect on Early-Exercise Derivatives -- 9.1.6.Reducing Our Indetermination in Pricing Bermudans: Liquid European Swaptions -- 9.2.The Evolution of the Forward Smiles -- 10.When the Payoff is Wrong -- 10.1.The Link Between Model Errors and Payoff Errors -- 10.2.The Right Payoff at Default: The Impact of the Closeout Convention -- 10.2.1.How Much Will be Paid at Closeout, Really? -- 10.2.2.What the Market Says and What the ISDA Says -- 10.2.3.A Quantitative Analysis of the Closeout -- 10.2.4.A Summary of the Findings and Some Conclusions on Payoff Uncertainty -- 10.3.Mathematical Errors in the Payoff of Index Options --
Contents note continued: 10.3.1.Too Much Left Out -- 10.3.2.Too Much Left In -- 10.3.3.Empirical Results with the Armageddon Formula -- 10.3.4.Payoff Errors and Armageddon Probability -- 11.Model Arbitrage -- 11.1.Introduction -- 11.2.Capital Structure Arbitrage -- 11.2.1.The Credit Model -- 11.2.2.The Equity Model -- 11.2.3.From Barrier Options to Equity Pricing -- 11.2.4.Capital-structure Arbitrage and Uncertainty -- 11.3.The Cap-Swaption Arbitrage -- 11.4.Conclusion: Can We Use No-Arbitrage Models to Make Arbitrage? -- 12.Appendix -- 12.1.Random Variables -- 12.1.1.Generating Variables from Uniform Draws -- 12.1.2.Copulas -- 12.1.3.Normal and Lognormal -- 12.2.Stochastic Processes -- 12.2.1.The Law of Iterated Expectation -- 12.2.2.Diffusions, Brownian Motions and Martingales -- 12.2.3.Poisson Process -- 12.2.4.Time-dependent Intensity -- 12.3.Useful Results from Quantitative Finance -- 12.3.1.Black and Scholes (1973) and Black (1976) -- 12.3.2.Change of Numeraire.
Abstract:
"A guide to the validation and risk management of quantitative models used for pricing and hedging. Whereas the majority of quantitative finance books focus on mathematics and risk management books focus on regulatory aspects, this book addresses the elements missed by this literature--the risks of the models themselves. This book starts from regulatory issues, but translates them into practical suggestions to reduce the likelihood of model losses, basing model risk and validation on market experience and on a wide range of real-world examples, with a high level of detail and precise operative indications"--
"Understanding and Managing Model Risk is a guide to the validation and risk management of quantitative models used for pricing and hedging"--
Added Author: