PDE approach to valuation and hedging of credit derivatives

This paper presents a PDE approach in a Markovian setting to hedge defaultable derivatives. The arbitrage price and the hedging strategy for an attainable contingent claim are described in terms of solutions of a pair of coupled PDEs. For some standard examples of defaultable claims, we provide explicit formulae for prices and hedging strategies.     

Modeling default risk with support vector machines

Predicting default risk is important for firms and banks to operate successfully. There are many reasons to use nonlinear techniques for predicting bankruptcy from financial ratios. Here we propose the so-called Support Vector Machine (SVM) to predict the default risk of German firms. Our analysis is based on the Creditreform database. In all tests performed in this paper the nonlinear model classified by SVM exceeds the benchmark logit model, based on the same predictors, in terms of the performance metric, AR. The empirical evidence is in favor of the SVM for classification, especially in the linear non-separable case. The sensitivity investigation and a corresponding visualization tool reveal that the classifying ability of SVM appears to be superior over a wide range of SVM parameters. In terms of the empirical results obtained by SVM, the eight most important predictors related to bankruptcy for these German firms belong to the ratios of activity, profitability, liquidity, leverage and the percentage of incremental inventories. Some of the financial ratios selected by the SVM model are new because they have a strong nonlinear dependence on the default risk but a weak linear dependence that therefore cannot be captured by the usual linear models such as the DA and logit models.     

Knowing the unknowable and contested terrains in accounting

Creating visibilities and breaking silences are powerful legacies of critical accounting research and education. This paper, promoting that we further develop our understandings of how ideas are created, reveals how language is nuanced, power is embed in accounting technology, and accounting education crafts and restricts meaning. Particular ways of knowing in accounting education are appraised as well as emerging approaches to critical and ethical accounting education in order to deliberate: how can we foster a truly critical framework by which educators and students can “think different” and what can be done to promote sustainable, principled, and nuanced business practices? Our views of the morality of our world, how social structures affect ways of knowing, and what disrupts and challenges the status quo are particularly of concern to promote social transformation and justice.     

Can the academic literature contribute to the debate over mandatory audit firm rotation?

Recently, the Public Company Accounting Oversight Board (PCAOB) issued a concept release soliciting public recommendations to improve auditor independence and audit quality (PCAOB, 2011). The focus of the release is on mandatory audit firm rotation (MAFR) with a request for commentaries addressing the advantages and disadvantages of MAFR. In this paper, we briefly summarize the recent literature on mandatory audit firm rotation and suggest how it can be useful to regulators as they consider the implementation of mandatory rotation. We find that the conclusions reached about the possible effectiveness of MAFR appear to depend on the type of data used (voluntary vs. mandatory auditor changes), suggesting that regulators should exercise care when drawing inferences from past audit firm rotation research.     

How AIS can progress along with ontology research in IS

Recent years have witnessed a strong and growing interest in the computer science (CS) and information systems (IS) disciplines in applying and extending ontological principles to various CS/IS domains such as knowledge representation, natural language processing, conceptual modeling, and IS development. Similar interest and work have also been observed in accounting information systems (AIS) research. Though ontology research in AIS has enjoyed sustained interest and produced some significant results, there is relatively little incorporation of recent developments in CS/IS ontology research into AIS. This paper provides an overview of some leading areas of ontology research in CS/IS and AIS in an attempt to bridge this gap. The main objectives of this paper are to (1) introduce CS/IS ontology research, (2) highlight areas of future research in AIS where CS/IS ontology research developments can be used to address important and pressing issues, and (3) broaden an area of research where AIS can make unique contributions to distinguish itself.     

A Regime-Switching Model of Long-Term Stock Returns

Abstract

In this paper I first define the regime-switching lognormal model. Monthly data from the Standard and Poor’s 500 and the Toronto Stock Exchange 300 indices are used to fit the model parameters, using maximum likelihood estimation. The fit of the regime-switching model to the data is compared with other common econometric models, including the generalized autoregressive conditionally heteroskedastic model. The distribution function of the regime-switching model is derived. Prices of European options using the regime-switching model are derived and implied volatilities explored. Finally, an example of the application of the model to maturity guarantees under equity-linked insurance is presented. Equations for quantile and conditional tail expectation (Tail-VaR) risk measures are derived, and a numerical example compares the regime-switching lognormal model results with those using the more traditional lognormal stock return model.     

Distortion Risk Measures and Economic Capital

Abstract

To provide incentive for active risk management, it is argued that a sound coherent distortion risk measure should preserve some higher degree stop-loss orders, at least the degree-three convex order. Such risk measures are called tail-preserving risk measures. It is shown that, under some common axioms and other plausible conditions, a tail-preserving coherent distortion risk measure identifies necessarily with the Wang right-tail measure or the expected value measure. This main result is applied to derive an optimal economic capital formula.     

The Effect of Policyholder Transfer Behavior on the Value of Guaranteed Minimum Death Benefits

Abstract

Variable annuity contracts frequently include both guaranteed minimum death benefit (GMDB) options and options to transfer funds between fixed and variable accounts. We model the difference between fixed and variable rates as the primary determinant of policyholder transfer behavior. We find that people tend to transfer their money into variable accounts at about 39% of the rate that would be required to maintain constant percentage rebalancing, but with the opposite sign. If these transfers are not taken into account, the GMDB options on the variable accounts will be overvalued and overhedged. Ignoring this effect can have a substantial impact on the size of the futures portfolio needed to hedge this risk and a nonnegligible impact on the earnings of the variable annuity portfolio.     

Market-Consistent Valuation and Funding of Cash Balance Pensions

Cash balance pension benefits are accumulated at guaranteed crediting rates, usually based on yields on government securities. Viewed as a financial liability, the benefit is a form of interest rate derivative, which can be valued using financial models and theory. In this article, we derive the market value for a range of commonly used crediting rates, assuming the accrued benefit liability comprises the past contributions, allowing for full interest credits up to a known future retirement date. We use the Hull-White interest rate model to determine crediting rates and to determine the market value. We explore the risks associated with different crediting rate choices by evaluating the liability using market data from 1998 to 2013. We propose two other approaches to the accrued benefit. The first approach assumes the accrued benefit comprises past contributions with interest up to the valuation date, but no future interest credits. Future credits on past contributions are assumed funded through future contributions. The second method projects all contributions and interest to retirement and assumes equal units of accrual of this projected benefit in each year of service. We compare the three approaches through numerical examples.     

Time varying country risk: an assessment of alternative modelling techniques

Three different techniques for the estimation of a time-varying beta are investigated: a bivariate GARCH model, the Schwert and Seguin approach, and the Kalman filter method. These approaches are applied to a set of monthly Morgan Stanley country index data over the period 1970 to 1995 and their relative performances compared. In-sample forecast tests of the performance of each of these methods for generating conditional beta suggest that the GARCH-based estimates of risk generate the lowest forecast error although these are not necessarily significantly less than those generated by the other techniques considered.