STOCK RETURNS AND VOLATILITY ON CHINA'S STOCK MARKETS

We examine time‐series features of stock returns and volatility, as well as the relation between return and volatility in four of China's stock exchanges. Variance ratio tests reject the hypothesis that stock returns follow a random walk. We find evidence of long memory of returns. Application of GARCH and EGARCH models provides strong evidence of time‐varying volatility and shows volatility is highly persistent and predictable. The results of GARCH‐M do not show any relation between expected returns and expected risk. Daily trading volume used as a proxy for information arrival time has no significant explanatory power for the conditional volatility of daily returns. JEL classification: G15     

Investment Opportunities and the Relation Between Equity Value and Employees' Bonus

A sample of firms where employee stock options and other long‐term incentives are absent but an annual bonus is required is examined. A positive relation is found between firm equity value and stock bonus but not cash bonus. The positive relation is stronger when the firm has greater investment opportunities. Additionally, the relation is shown to be nonlinear in the sense that the marginal effect of stock bonus on equity value is positive but decreasing (negative) when the stock bonus is below (above) the breakpoint. Overall, the annual stock bonus is valued positively by investors even though it is linked to the firm's contemporaneous but not future performance.     

Managing the environmental adaptation process in supplier–customer relationships

This paper details the results and managerial implications from four case studies, which examine how the environmental adaptation process (EAP) is managed within business‐to‐business relationships. The research uses models of supplier–customer interaction and inter‐organization cooperation in order to explore inter‐firm relationships and the process of adaptation. The research findings show that either party might pursue adaptations and also establishes features of the process itself as well as identifying factors that can facilitate or hinder the introduction of environmental changes. Arriving at a satisfactory outcome to the adaptation process can be determined by individual company and relationship characteristics, as well as the behaviour and experience of those managers involved in the process. Guidelines for the management of the process of environmental adaptation are proposed. Copyright © 2001 John Wiley & Sons, Ltd and ERP Environment     

General‐to‐Specific Model Selection Procedures for Structural Vector Autoregressions*

Structural vector autoregressive (SVAR) models have emerged as a dominant research strategy in empirical macroeconomics, but suffer from the large number of parameters employed and the resulting estimation uncertainty associated with their impulse responses. In this paper, we propose general‐to‐specific (Gets) model selection procedures to overcome these limitations. It is shown that single‐equation procedures are generally efficient for the reduction of recursive SVAR models. The small‐sample properties of the proposed reduction procedure (as implemented using PcGets) are evaluated in a realistic Monte Carlo experiment. The impulse responses generated by the selected SVAR are found to be more precise and accurate than those of the unrestricted VAR. The proposed reduction strategy is then applied to the US monetary system considered by Christiano, Eichenbaum and Evans (Review of Economics and Statistics, Vol. 78, pp. 16–34, 1996) . The results are consistent with the Monte Carlo and question the validity of the impulse responses generated by the full system.     

Estimates of the demand for medical care under different functional forms

We estimate price and income elasticities from a linear, log-linear, and the almost ideal demand model (with and without an adjustment for selectivity bias) in an effort to show that special attention should be paid to the underlying assumptions of consumer behaviour when estimating a medical care demand model. The literature on medical care utilization is extended by incorporating two major components of spending as separate demands in a system of medical care spending. We find that estimates of elasticities vary depending on the functional form of the estimating equation, thus questioning the usefulness for policy purposes of single estimates of elasticities.     

WITHDRAWN SPIN‐OFFS: AN EMPIRICAL ANALYSIS

We examine market reaction to corporate spin‐offs that are eventually withdrawn. These spin‐offs do not experience the significant positive share price response reported for spin‐offs generally. The overall market reaction to both the initial spin‐off announcement and the withdrawal announcement is not significant. When a reason is provided for withdrawing a spin‐off, there is a significant positive market reaction; otherwise, there is a significant negative reaction. Firms that withdraw a spin‐off without stating a reason experience significant deterioration in industry‐adjusted operating performance in the three years following the withdrawal. These results indicate the market can anticipate the viability of withdrawn spin‐offs at the time of the initial announcement. JEL classification: G34     

OPENING RETURNS,NOISE, AND OVERREACTION

In this article a partial‐adjustment model, which shows how equity prices fail to adjust instantaneously to new information, is estimated using a Kalman filter. For the components of the Dow Jones Industrial 30 index I aim to identify whether overreaction or noise is the cause of serial correlation and high volatility associated with opening returns. I find that the tendency for overreaction in opening prices is much stronger than for closing prices; therefore, overreaction rather than noise may account for differences in the return behavior of opening and closing returns. JEL classification: G15     

Social marketing on AIDS: using Transtheoretical model to understand current condom usage among commercial drivers in Accra,Ghana

• This is an exploratory research to utilise the Transtheoretical model to assess condom usage intentions among commercial drivers in Ghana. A convenience‐based non‐probability sampling method was employed, and a face‐to‐face questionnaire was administered on 132 commercial drivers in Accra. The analysis of variance and one sample t‐test statistical method was employed to establish relationship between variables based on the Transtheoretical model. The result reveals that over 71.9% of commercial drivers are at precontemplation, contemplation and preparation stages. This means that most commercial drivers interviewed have not yet taken action to use condoms to protect themselves against HIV/AIDS. The findings of the study constitute a series of marketing ideas, useful in decision making with social marketing organisations.

Copyright © 2013 John Wiley & Sons, Ltd.     

无线网络技术在铁路系统中的应用

在阐述无线网络技术在铁路上应用现状的基础上,分析无线列车调度通信系统、GSM-R铁路无线通信系统的实际应用及发展前景,最后对无线局域网的技术标准及其应用范围进行论述.