Forecasting volatility: Roles of sampling frequency and forecasting horizon

This study empirically tests how and to what extent the choice of the sampling frequency, the realized volatility (RV) measure, the forecasting horizon and the time‐series model affect the quality of volatility forecasting. Using highly synchronous executable quotes retrieved from an electronic trading platform, the study avoids the influence of various market microstructure factors in measuring RV with high‐frequency intraday data and in inferring implied volatility (IV) from option prices. The study shows that excluding non‐trading‐time volatility produces significant downward bias of RV by as much as 36%. Quality of prediction is significantly affected by the forecasting horizon and RV model, but is largely immune from the choice of sampling frequency. Consistent with prior research, IV outperforms time‐series forecasts; however, the information content of historical volatility critically depends on the choice of RV measure. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark     

On the unique features of post-disaster humanitarian logistics

Logistic activity can be thought of as a socio-technical process whereby a social network of individuals orchestrates a series of technical activities using supporting systems such as transportation and communications. To understand the functioning of the entire system requires proper consideration of all its components. We identify seven key components: the objectives being pursued, the origin of the commodity flows to be transported, knowledge of demand, the decision-making structure, periodicity and volume of logistic activities, and the state of the social networks and supporting systems. Based on our analysis of the differences between commercial and humanitarian logistics, we pinpoint research gaps that need to be filled to enhance both the efficiency of humanitarian logistics and the realism of the mathematical models designed to support it.We argue that humanitarian logistics is too broad a field to fit neatly into a single definition of operational conditions. At one end of the spectrum we find humanitarian logistic efforts of the kind conducted in long-term disaster recovery and humanitarian assistance, where operational efficiency – akin to commercial logistics – is a prime consideration. At the other, post-disaster humanitarian logistic operations involved in disaster response and short-term recovery activities represent a vastly different operational environment, often in chaotic settings where urgent needs, life-or-death decisions and scarce resources are the norm. The huge contrast between these operational environments requires that they be treated separately.     

Re-examination of interest rate sensitivity of commercial bank stock returns using a random coefficient model

This article develops and tests a random coefficient two-index model for commercial bank stock returns which controls for the time-varying interest rate sensitivity caused by a bank's changing maturity profile. Using a sample of 51 actively traded commercial banks, the seemingly unrelated regression results provide evidence that commercial bank stock returns are significantly interest rate sensitive. The effect of interest rate changes on bank stock returns is found to be positively related to the maturity mismatch between the bank's assets and liabilities, when the proxy for interest rate changes and the proxy for maturity mismatch are compatible to each other.This article was written while I was a doctoral student at the University of North Carolina at Chapel Hill. It was presented at the 1989 FMA Annual Meeting in Boston.     

On the process of risk reduction through diversification

This paper examines the celebrated empirical study of J.L. Evans and S.H. Archer on the relationship between risk reduction and the size of a portfolio. By specifying a suitable return generation model, this widely supported empirical result is shown to be a statistical consequence of their methodology. The mathematical structure of their methodology is presented together with some fresh empirical results on this relationship. Finally the question as to whether a larger number of assets are required in order to achieve the same level of diversification for high beta securities is examined based on a sample of U.K. securities. The results of the tests would not appear to be in support of such a proposition.     

Taxes, clientele effect of dividend and risk, return linearity

This paper extends the equivalence relationship between risk/return linearity and portfolio efficiency as derived in Roll (1977) to the case where there is differential taxation affecting investors optimal portfolio choice. Following the formulation of Brennan (1970a), the fundamental linearity relationship is derived which raises serious doubts to the testability of the extendedCAPM that accounts for the effect of differential taxation. Finally by aggregating other imperfections as well as differential taxation into a dividend yield constraint, a different version of theCAPM is derived which offers alternative interpretations of the existing empirical results on the subject.     

China＇s Outward Direct and Portfolio Investments

This paper analyzes developments and trends related to China's outward direct and financial investments by examining Chinese firms’overseas acquisitions, China's holdings of US Treasury securities, and the recently formally launched Qualified Domestic Institutional Investor programs. Strategies should be developed to reach optimal decisions for both direct and portfolio investments. We argue that China should have a longer‐term view for both direct and portfolio investments, enabling China to become the leader in Asia while maintaining its sustainable growth objective. China should invest heavily in the development of the Asian bond market and the Asian Currency Fund when making both portfolio and direct investment decisions.     

IMPACT OF DIVIDEND‐PROTECTED EMPLOYEE STOCK OPTIONS ON PAYOUT POLICIES: EVIDENCE FROM TAIWAN

Abstract. This study used a sample of 1035 Taiwanese firms to examine the impact of dividend protected employee stock options on stock repurchase and cash dividend policies from 2000 to 2005. This study finds a positive relationship between cash dividends and executive options, implying that executives holding stock options might prefer to distribute cash dividends to boost the stock price. This result, unlike in earlier studies, arises from the dividend protected characteristic of Taiwanese employee stock options. Finally, free cash flow, firm profitability, level of debt, investment opportunities and firm size are found to considerably influence payout decisions.     

Adjusting for the intervalling effect bias in beta: A Test using Paris Bourse Data

This paper uses a sample of daily returns data from the Paris Bourse to test the predictions of and adjustment procedures implied by the Cohen-Hawawini-Maier-Schwartz-Whitcomb (1983a,b) model of the intervalling effect bias in OLS beta estimates. CHMSW show that the bias diminishes asymptotically to zero as the differencing interval increases and that the sign of the bias depends on a stock's relative value of shares outstanding. We employ the three-pass regression procedure of CHMSW (1983b), but we test a broader set of second pass functional forms and use the Box-Cox (1964) transformation model to verify our chosen form. The CHMSW adjustment procedures are compared with that of Scholes-Williams (1977), and the latter is shown to contain a significant intervalling effect bias.     

The impact of the Internet on human activity–travel patterns: analysis of gender differences using multi-group structural equation models

The widespread use of the Internet for conducting various types of activities may be leading to considerable change in people’s activity–travel patterns. Past studies, however, have left many issues unaddressed. Using an Internet-activity diary dataset and multi-group structural equation modeling, this study examines the complex interactions between different types of Internet and physical activities, with a special focus on gender differences and Internet maintenance and leisure activities. The results indicate that the impacts of Internet activities on people’s activity–travel patterns are significantly different across gender. In general, Internet use for maintenance purposes has a greater impact on women’s activity–travel in the physical world, while Internet use for leisure purposes affects men’s physical activities and travel to a greater extent. Further, breaking Internet activities down into different categories reveals some hidden patterns that would not have been detected if these different types of Internet activities were lumped together as a single category.     

Earnings quality: Some evidence on the role of auditor tenure and auditors’ industry expertise

Prior studies suggest that auditors with short tenure are associated with lower earnings quality because of the lack of client-specific knowledge and/or low balling. In this study, we examine whether industry specialization of auditors and low balling affect the association between auditor tenure and earnings quality. We find that the association between shorter auditor tenure and lower earnings quality is weaker for firms audited by industry specialists compared to non-specialists. In addition, we do not find results consistent with the low balling explanation.