nep-rmg New Economics Papers
on Risk Management
Issue of 2012‒03‒14
eight papers chosen by
Stan Miles
Thompson Rivers University

  1. Shock on Variable or Shock on Distribution with Application to Stress-Tests By Dubecq, S.; Gourieroux, C.
  2. Forecasting Value-at-Risk Using Block Structure Multivariate Stochastic Volatility Models By Manabu Asai; Massimiliano Caporin; Michael McAleer
  3. The Current State of the Financial Sector and the Regulatory Framework in Asian Economies—The Case of the People’s Republic of China By Luo Ping
  4. Incorporating fat tails in financial models using entropic divergence measures By Santanu Dey; Sandeep Juneja
  5. The Value of Multivariate Model Sophistication: An Application to pricing Dow Jones Industrial Average Options By Jeroen Rombouts; Lars Peter Stentoft; Francesco Violente
  6. A coopetitive approach to financial markets stabilization and risk management By Carfì, David; Musolino, Francesco
  7. Portfolioallokation: Einbezug verschiedener Assetklassen By Herz, Christian; Neunert, Daniela; Will, Sebastian; Wolf, Niko J.; Zwick, Tobias
  8. Improving Classifier Performance Assessment of Credit Scoring Models By Raffaella Calabrese

  1. By: Dubecq, S.; Gourieroux, C.
    Abstract: The shocks on a stochastic system can be defined by means of either distribution, or variable. We relate these approaches and provide the link between the global and local effects of both types of shocks. These methodologies are used to perform stress-tests on the portfolio of financial institutions by means of shocks on systematic factors, for which we distinguish the cases of crystallized and optimally updated portfolios. The approach is illustrated by an analysis of the risk of sovereign bonds of the Eurozone.
    Keywords: Shock, Copula, Extreme Risk, Stress-Test, Factor Model, Systemic Risk, Portfolio Management, Sovereign Bonds.
    JEL: C10 E37 G11 G17
    Date: 2012
  2. By: Manabu Asai (Soka University / Faculty of Economics); Massimiliano Caporin (Department of Economics and Management “Marco Fanno” University of Padova, Italy.); Michael McAleer (Econometric Institute, Erasmus School of Economics, Erasmus University Rotterdam and Tinbergen Institute, The Netherlands, Department of Quantitative Economics, Complutense University of Madrid, and Institute of Economic Research, Kyoto University)
    Abstract: Most multivariate variance or volatility models suffer from a common problem, the “curse of dimensionality”. For this reason, most are fitted under strong parametric restrictions that reduce the interpretation and flexibility of the models. Recently, the literature has focused on multivariate models with milder restrictions, whose purpose was to combine the need for interpretability and efficiency faced by model users with the computational problems that may emerge when the number of assets is quite large. We contribute to this strand of the literature proposing a block-type parameterization for multivariate stochastic volatility models. The empirical analysis on stock returns on US market shows that 1% and 5 % Value-at-Risk thresholds based on one-step-ahead forecasts of covariances by the new specification are satisfactory for the period includes the global financial crisis.
    Keywords: block structures; multivariate stochastic volatility; curse of dimensionality; leverage effects; multi-factors; heavy-tailed distribution.
    JEL: C32 C51 C10
    Date: 2012
  3. By: Luo Ping (Asian Development Bank Institute (ADBI))
    Abstract: Reform of financial regulation is a priority on the international agenda. At the call of the Group of Twenty Finance Ministers and Central Bank Governors (G-20), a number of new international standards have been issued, most notably Basel III. As a member of the G-20, the Financial Stability Board (FSB), and the Basel Committee on Banking Supervision, the People’s Republic of China (PRC) is now on a faster track in adopting international standards. However, the key issue for the PRC—as well as many other emerging markets—is to how to keep focused on the domestic policy agenda while adopting the new global standards. Fortunately, the PRC’s financial system has proved resilient to the recent financial crisis. As a result, banks in the PRC find it quite easy to meet the new Basel III capital and liquidity standards. Basel III is only part of an effective regulatory framework. While phasing in Basel III, the PRC needs other prudential tools such as a new provision ratio, in addition to the provision coverage ratio. Activity restriction will be another effective tool with the potential to prevent banks from becoming too complicated for bankers to manage and for the regulator to supervise. As we work hard to improve the effectiveness of the regulatory system at both the global and national level, we should remind ourselves of the importance of keeping the balance between enhanced regulation and promoting financial innovation—without the pendulum swinging too far.
    Keywords: financial regulation, China, financial sector, banking supervision, regulatory framework
    JEL: E44 E52 E58 G18 G28
    Date: 2011–09
  4. By: Santanu Dey; Sandeep Juneja
    Abstract: In the existing financial literature, entropy based ideas have been proposed in portfolio optimization, in model calibration for options pricing as well as in ascertaining a pricing measure in incomplete markets. The abstracted problem corresponds to finding a probability measure that minimizes the relative entropy (also called $I$-divergence) with respect to a known measure while it satisfies certain moment constraints on functions of underlying assets. In this paper, we show that under $I$-divergence, the optimal solution may not exist when the underlying assets have fat tailed distributions, ubiquitous in financial practice. We note that this drawback may be corrected if `polynomial-divergence' is used. This divergence can be seen to be equivalent to the well known (relative) Tsallis or (relative) Renyi entropy. We discuss existence and uniqueness issues related to this new optimization problem as well as the nature of the optimal solution under different objectives. We also identify the optimal solution structure under $I$-divergence as well as polynomial-divergence when the associated constraints include those on marginal distribution of functions of underlying assets. These results are applied to a simple problem of model calibration to options prices as well as to portfolio modeling in Markowitz framework, where we note that a reasonable view that a particular portfolio of assets has heavy tailed losses may lead to fatter and more reasonable tail distributions of all assets.
    Date: 2012–03
  5. By: Jeroen Rombouts; Lars Peter Stentoft; Francesco Violente
    Abstract: We assess the predictive accuracy of a large number of multivariate volatility models in terms of pricing options on the Dow Jones Industrial Average. We measure the value of model sophistication in terms of dollar losses by considering a set 248 multivariate models that differ in their specification of the conditional variance, conditional correlation, and innovation distribution. All models belong to the dynamic conditional correlation class which is particularly suited because it allows to consistently estimate the risk neutral dynamics with a manageable computational effort in relatively large scale problems. It turns out that the most important gain in pricing accuracy comes from increasing the sophistication in the marginal variance processes (i.e. nonlinearity, asymmetry and component structure). Enriching the model with more complex correlation models, and relaxing a Gaussian innovation for a Laplace innovation assumption improves the pricing in a smaller way. Apart from investigating directly the value of model sophistication in terms of dollar losses, we also use the model confidence set approach to statistically infer the set of models that delivers the best pricing performance. <P>
    Keywords: Option pricing, economic loss, forecasting, multivariate GARCH, model confidence set,
    JEL: C10 C32 C51 C52 C53 G10
    Date: 2012–02–01
  6. By: Carfì, David; Musolino, Francesco
    Abstract: The aim of this paper is to propose a methodology to stabilize the financial markets by adopting Game Theory, in particular, the Complete Study of a Differentiable Game and the new mathematical model of Coopetitive Game, proposed recently in the literature by D. Carfì. Specifically, we will focus on two economic operators: a real economic subject and a financial institute (a bank, for example) with a big economic availability. For this purpose we will discuss about an interaction between the two above economic subjects: the Enterprise, our first player, and the Financial Institute, our second player. The only solution which allows both players to win something, and therefore the only one collectively desirable, is represented by an agreement between the two subjects: the Enterprise artificially causes an inconsistency between spot and future markets, and the Financial Institute, who was unable to make arbitrages alone, because of the introduction by the normative authority of a tax on economic transactions (that we propose to stabilize the financial market, in order to protect it from speculations), takes the opportunity to win the maximum possible collective (social) sum, which later will be divided with the Enterprise by contract. We propose hereunder two kinds of agreement: a fair transferable utility agreement on the an initial natural interaction and a same type of compromise on a quite extended coopetitive context.
    Keywords: Financial Markets and Institutions; Financing Policy; Financial Risk; Financial Crises; Game Theory; Arbitrages; Coopetition
    JEL: D53 C7 E44 G32 G01
    Date: 2012
  7. By: Herz, Christian; Neunert, Daniela; Will, Sebastian; Wolf, Niko J.; Zwick, Tobias
    Abstract: Die Stabilität der Europäischen Währungsunion ist durch die derzeit angespannte Haushaltslage und den hohen Verschuldungsgrad einiger Mitgliedstaaten in Frage gestellt. Diese Arbeit untersucht die Auswirkungen verschiedener (Krisen-)Szenarien auf das Portfolio eines durchschnittlichen deutschen Privatanlegers. Zum Zweck der Anlageoptimierung wird die Entwicklung des varianzminimalen Portfoliooptimierungsansatzes nach Markowitz und einer Gleichgewichtungsmethode (1/n-Heuristik) mit fünf ausgewählten Anlageklassen analysiert. Anschließend werden die Entwicklungen der Portfolios über verschiedene Zeiträume für drei vergangenheitsorientierte Szenarien betrachtet. Im Ergebnis kann festgestellt werden, dass das heuristische Portfolio und das Minimum-Varianz-Portfolio (MVP) die durchschnittlichen Privatanlegerportfolios im Bad-Case-Szenario sowohl in Bezug auf die Rendite als auch auf die Volatilität dominieren. Da die untersuchten Privatanlegerportfolios exklusiv aus Aktien- und Rentenwerten bestehen, weisen sie im Good-Case- und Mid-Case-Szenario höhere Renditen als die Benchmark-Portfolios, aber gleichzeitig auch eine höhere Volatilität auf. Insgesamt kann abgeleitet werden, dass eine Anlage in Gold und insbesondere in Währungen die Portfolios stabilisiert. Die Darstellung eines Portfolios mit geringer Volatilität könnte daher vereinfachend und transparent mittels des heuristischen Portfolios umgesetzt werden. -- High levels of public debt have recently unsettled the European Monetary Union. This paper examines the effect of different downside scenarios on the portfolio of an average German investor. To identify the right asset allocation, this paper analyzes the minimal variance portfolio optimization according to Markowitz as well as a heuristic method (whereby each asset class is weighted equally) with five different asset classes. Subsequently, the analysis examines the development of these portfolios for three historic scenarios over different periods of time. In summary, this paper concludes that investments in the heuristic portfolio and in the minimum variance portfolio provide both a higher return and lower volatility in the bad case scenario, compared to the average portfolio of a private investor. Since the portfolios of private investors exclusively comprise shares and bonds, these portfolios display a higher return, yet also higher volatility, in the good case and mid case scenarios. Overall, analysis reveals that allocations into gold and especially into currencies stabilize the portfolios of an average German investor. As a result, the 1/n-heuristic method offers a simplified and transparent way to design a low volatility portfolio.
    Keywords: Portfolio Management,Asset Allocation,Private Geldanlage,Risikominimierung
    JEL: G11 G13
    Date: 2012
  8. By: Raffaella Calabrese (Dynamics Lab, Geary Institute, University College Dublin)
    Abstract: In evaluating credit scoring predictive power it is common to use the Re-ceiver Operating Characteristics (ROC) curve, the Area Under the Curve(AUC) and the minimum probability-weighted loss. The main weakness of the rst two assessments is not to take the costs of misclassication errors into account and the last one depends on the number of defaults in the credit portfolio. The main purposes of this paper are to provide a curve, called curve of Misclassication Error Loss (MEL), and a classier performance measure that overcome the above-mentioned drawbacks. We prove that the ROC dominance is equivalent to the MEL dominance. Furthermore, we derive the probability distribution of the proposed predictive power measure and we analyse its performance by Monte Carlo simulations. Finally, we apply the suggested methodologies to empirical data on Italian Small and Medium Enterprisers.
    Keywords: Performance Assessment, Credit Scoring Modules, Monte Carlo simulations, Italian Enterprisers
    Date: 2012–02–20

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