A Note on Computation of Implied Volatility

This is a note on computation of the implied volatility in theBlack–Scholes formula to evaluate an accuracy of the computation.     

A Cautionary Note on Natural Hedging of Longevity Risk

In this article, we examine the so-called natural hedging approach for life insurers to internally manage their longevity risk exposure by adjusting their insurance portfolio. In particular, unlike the existing literature, we also consider a nonparametric mortality forecasting model that avoids the assumption that all mortality rates are driven by the same factor(s).

Our primary finding is that higher order variations in mortality rates may considerably affect the performance of natural hedging. More precisely, although results based on a parametric single factor model—in line with the existing literature—imply that almost all longevity risk can be hedged, results are far less encouraging for the nonparametric mortality model. Our finding is supported by robustness tests based on alternative mortality models.     

Implied Spot Rates as Predictors of Currency Returns: A Note

Currency call option transactions data and the Black-Scholes option pricing model, as modified by Merton for continuous dividends and as adapted to currency options by Biger and Hull and by Garman and Kohlhagen, are used to imply spot foreign exchange rates. The proportional deviation between implied and simultaneously observed spot rates is found to be a direct and statistically significant determinant of subsequent returns on foreign currency holdings after controlling for interest rate differentials. Further, an ex ante trading rule reveals that the additional information contained in implied rates often is sufficient to generate significant economic profits.     

Understanding the Implied Volatility Surface for Options on a Diversified Index

This paper describes a two-factor model for a diversified index that attempts to explain both the leverage effect and the implied volatility skews that are characteristic of index options. Our formulation is based on an analysis of the growth optimal portfolio and a corresponding random market activity time where the discounted growth optimal portfolio is expressed as a time transformed squared Bessel process of dimension four. It turns out that for this index model an equivalent risk neutral martingale measure does not exist because the corresponding Radon-Nikodym derivative process is a strict local martingale. However, a consistent pricing and hedging framework is established by using the benchmark approach. The proposed model, which includes a random initial condition for market activity, generates implied volatility surfaces for European call and put options that are typically observed in real markets. The paper also examines the price differences of binary options for the proposed model and their Black-Scholes counterparts. Mathematics Subject Classification: primary 90A12; secondary 60G30; 62P20 JEL Classification: G10, G13     

A Note on the Term Structure of Implied Volatilities for the Yen/U.S. Dollar Currency Option

This paper tests the relationship between short dated and long dated implied volatilities obtained from Tokyo market currency option prices by employing three different volatility models: a mean reverting model, a GARCH model, and an EGARCH model. We document evidence that long dated average expected volatility is higher than that predicted by the term structure relationship during the dramatic appreciation of yen/dollar exchange in the early 1990's. This revised version was published online in August 2006 with corrections to the Cover Date.     

An Optimal Product Mix for Hedging Longevity Risk in Life Insurance Companies: The Immunization Theory Approach

This article investigates the natural hedging strategy to deal with longevity risks for life insurance companies. We propose an immunization model that incorporates a stochastic mortality dynamic to calculate the optimal life insurance–annuity product mix ratio to hedge against longevity risks. We model the dynamic of the changes in future mortality using the well‐known Lee–Carter model and discuss the model risk issue by comparing the results between the Lee–Carter and Cairns–Blake–Dowd models. On the basis of the mortality experience and insurance products in the United States, we demonstrate that the proposed model can lead to an optimal product mix and effectively reduce longevity risks for life insurance companies.     

Developing a House Price Index for The Netherlands: A Practical Application of Weighted Repeat Sales

This paper describes the development of a house price index that has been introduced in May 2005 in The Netherlands. This monthly index, called Woningwaarde Index Kadaster (House Price Index Kadaster), is designed to detect changes in the price of the overall stock of owner-occupied homes. Fifty-five indices are calculated: one overall index, four regional indices, 12 provincial indices and 38 indices based on combinations of region/province and dwelling type. We used Case and Shiller’s geometric Weighted Repeat Sales Model to calculate monthly house price indices. We used recorded data on the sales of over 500,000 owner-occupied homes in The Netherlands, all representing repeat sales between January 1993 and December 2006. The accuracy of the index was determined using the 95% confidence interval. We observed that accuracy might become a problem in smaller sub samples. Revision volatility was explored by comparing the index values computed from all available data until December 2005 with the index values computed from the data available until December 2006. Our analysis showed that revision volatility does not seem to be a major problem to the index. We also explored heteroskedasticity in the Repeat Sales method but did not find conclusive evidence for the proposed heteroskedasticity. Given our target (a geometric mean index value) and the characteristics of the dataset (very large but without property characteristics) the Repeat Sales Method seems to be adequate for calculating a house price index for The Netherlands.

长寿风险对寿险和年金产品定价的对冲效应研究

作为老龄社会的重要风险,长寿风险专题研究是近20年来公共养老金领域、保险公司关注的热点。长寿风险引发的保险公司寿险产品定价高估和年金产品定价低估之间存在潜在的自然对冲效应。为了量化这种对冲效应的长期影响,本文基于构建的同时涵盖低龄、高龄和超高龄在内的整个生命跨度的全年龄人口动态死亡率模型,采用对冲弹性量化终身寿险与终身年金、两全保险与定期年金、递延寿险与递延年金三类保障型寿险产品和养老型年金产品对冲效应的动态演变,并通过敏感性分析扩展探讨利率变化对对冲效应的长期影响。研究发现,从单位寿险和年金产品组合的净对冲效应来看,由于保险公司的产品定价区分了性别差异,使得女性的对冲效应更明显,因而女性对应的产品组合中的长寿风险对保险公司的影响更不显著。作为系统性风险,利率风险和长寿风险也存在对冲,利率上升能抵消或对冲长寿风险的影响,低利率下长寿风险更显著。     

The Dynamics of Implied Volatilities: A Common Principal Components Approach

It is common practice to identify the number and sources of shocks that move, e.g., ATM implied volatilities by principal components analysis. This approach, however, is likely to result in a loss of information, since the surface structure of implied volatilities is neglected. In this paper we analyze the implied volatility surface along maturity slices with a common principal components analysis (CPC), known from morphometrics. In CPC analysis, the space spanned by the eigenvectors is identical across groups, whereas variances associated with the common principal components vary. Our analysis shows that implied volatility surface dynamics can be traced back to a common eigenstructure in maturity slices. This empirical result is used to set up a factor model for implied volatility surface dynamics. This revised version was published online in June 2006 with corrections to the Cover Date.     

一起票据丢失案引发的法律问题

一起因工作人员疏忽导致的票据丢失案,竟引出令人眼花缭乱的当事人和复杂难辨的法律关系,本文对此一一评述。     

A Short Note on Updating the Grilli and Yang Commodity Price Index

The Grilli and Yang commodity price index is one of the mostwidely used commodity price series in the applied economicsliterature. This note provides some practical advice on updatingthis data series by listing the base period index values, identifyingrelevant data sources, and describing a method for computingsubindex weights.     

A Business Communication Module for an MBA Managerial Accounting Course: A Teaching Note

Abstract

This Teaching Note describes a two-hour-and-40-minute Business Communication module developed and used by the author over the past six years in an MBA Managerial Accounting course at a university in the USA. The module has two modest but important goals: to sensitize graduate accounting students to the importance of communication skills for professional success; and to provide students with a set of writing-improvement resources. The students' component of the module consists of a set of five readings and two learning resources. For teachers, a comprehensive set of PowerPoint slides is available from the author. The module is flexible in two respects: it can be used in graduate-level accounting courses other than Managerial Accounting; and a reduced version of in-class presentation time is possible by using only a sub-set of the PowerPoint slides, based on teacher preferences. Student responses to the module have been consistently positive and have supported continued use of the module into the future.     

The Determinants of Implied Volatility: A Test Using LIFFE Option Prices

This paper presents and tests a model of the volatility of individual companies' stocks, using implied volatilities derived from option prices. The data comes from traded options quoted on the London International Financial Futures Exchange. The model relates equity volatilities to corporate earnings announcements, interest-rate volatility and to four determining variables representing leverage, the degree of fixed-rate debt, asset duration and cash flow inflation indexation. The model predicts that equity volatility is positively related to duration and leverage and negatively related to the degree of inflation indexation and the proportion of fixed-rate debt in the capital structure. Empirical results suggest that duration, the proportion of fixed-rate debt, and leverage are significantly related to implied volatility. Regressions using all four determining variables explain approximately 30% of the cross-sectional variation in volatility. Time series tests confirm an expected drop in volatility shortly after the earnings announcement and in most cases a positive relationship between the volatility of the stock and the volatility of interest rates.     

The European monetary system: A Note

This paper investigates the performance of the EMS since its implementationin 1979. The statistical results suggest that there has been a significant decrease in bilateral and effective exchange rates variabilities of the participating countries. The test results also point toward a narrower divergence in the development of national monetary policies across ERM countries.     

Asymmetric Information, Long-Term Care Insurance, and Annuities: The Case for Bundled Contracts

This article examines the markets for long-term care insurance and annuities when there is asymmetric information and there are costs of administering contracts. Individuals differ in terms of their risk aversion. Risk-averse individuals take more care of their health and are relatively high risk in the annuities market and relatively low risk in the long-term care insurance market. In the long-term care insurance market, both separating and partial-pooling equilibria are possible. However, in the stand-alone annuity market, only separating equilibria are possible. We show, consistent with the extant empirical research, that in the presence of administration costs the more risk-averse individuals may buy relatively more long-term care insurance and more annuity coverage. Under the same assumptions, we show that equilibria exist with bundled contracts that Pareto dominate the outcomes with stand-alone contracts and are robust to competition from stand-alone contracts. The remaining empirical puzzle is to explain why bundled contracts are such a small share of the voluntary annuity market.     

The Scope of Accounting History: A Note

The writing of accounting history is increasingly dominated by writers in English discussing private-sector accounting in English-speaking countries of the nineteenth and twentieth centuries. This note emphasizes that the scope of accounting history is much wider than this.