Improved estimation of portfolio value‐at‐risk under copula models with mixed marginals

Portfolio value‐at‐risk (PVAR) is widely used in practice, but recent criticisms have focused on risks arising from biased PVAR estimates due to model specification errors and other problems. The PVAR estimation method proposed in this article combines generalized Pareto distribution tails with the empirical density function to model the marginal distributions for each asset in the portfolio, and a copula model is used to form a joint distribution from the fitted marginals. The copula–mixed distribution (CMX) approach converges in probability to the true marginal return distribution but is based on weaker assumptions that may be appropriate for the returns data found in practice. CMX is used to estimate the joint distribution of log returns for the Taiwan Stock Exchange (TSE) index and the associated futures contracts on SGX and TAIFEX. The PVAR estimates for various hedge portfolios are computed from the fitted CMX model, and backtesting diagnostics indicate that CMX outperforms the alternative PVAR estimators. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:997–1018, 2006     

废线路板热解处理研究现状

综述了近年来国内外废旧线路板热解处理技术研究现状。着重介绍了废旧线路板热解回收的工艺、热解产物、热解机理和动力学等方面的研究进展，讨论了热解回收技术存在的问题和发展方向。     

Financial Development and Economic Growth: Empirical Evidence from Six MENA Countries

This paper examines the causal relationship between financial development and economic growth for six Middle Eastern and North African countries (Algeria, Egypt, Israel, Morocco, Syria, and Tunisia), within a quadvariate vector autoregressive framework. We employ four different measures of financial development and apply the augmented vector autoregression vector (VAR) methodology of Toda and Yamamoto to test for Granger causality. Our empirical results strongly support the hypothesis that finance leads to growth in five out of the six countries. Only in Israel could weak support be found for causality running from economic growth to financial development but no causality in the other direction. These findings suggest the need to accelerate the financial reforms that have been launched since the mid 1980s and to improve the efficiency of these countries’ financial systems to stimulate saving/investment and, consequently, long‐term economic growth.     

Intraday return and volatility relationships between the Ibex 35 spot and futures markets

This paper analyses the intraday lead-lag relationships between returns and volatilities in the Ibex 35 spot and futures markets. Using hourly data, we jointly analyze the interactions between markets, estimating a bivariate error correction model with GARCH perturbations which captures stochastically the presence of an intraday U-shaped curve for both spot and futures market volatility. Our findings show a bidirectional causal relationship between market volatilities, with a positive feedback. This two-way transmission of volatility is consistent with market prices evolving according to a long-run equilibrium relationship, and shocks affecting both markets in the same direction. Our empirical results also support a unidirectional cross interaction from futures to spot market returns. This pattern suggests that the futures market leads the spot market in order to incorporate the arrival of new information.     

Worker Turnover, Job Turnover and Collective Bargaining in Spain

This paper analyses the relationship between the presence of organized labour in firms (approximated by the scope of collective bargaining) and the extent of gross worker and job flows. According to the voice theory of Freeman, those firms having a union presence will have lower worker mobility. However, there is no analysis of the effects of the presence of organized labour on gross job flows. Using a Spanish data base, we find evidence of the existence of a voice effect on gross worker flows but not clear support for a voice effect on gross job flows.     

Looking for contagion in currency futures markets

This article tests whether there are pure contagion effects in both conditional means and volatilities among British pound, Canadian dollar, Deutsche mark, and Swiss franc futures markets during the 1992 ERM crisis. A conditional version of international capital asset pricing model (ICAPM) in the absence of purchasing power parity (PPP) is used to control for economic fundamentals. The empirical results indicate that overall there are no mean spillovers among those futures markets, but they are detected during the crisis period. That is, past return shocks originating in any one of the four markets have no impact on the other three markets during the entire sample period, suggesting that these markets are weak‐form efficient. However, this weak‐form market efficiency fails to hold during the market turmoil, especially for British pound and Swiss franc, and the sources of contagion‐in‐mean effects are mainly due to the return shocks originating in three European currency futures markets. As for the contagion‐in‐volatility, it is detected for British pound only because its conditional volatility is influenced by the negative volatility shocks from Canadian dollar, Deutsche mark, and Swiss franc, with Deutsche mark playing the dominant role in generating these shocks. JEL Classifications: C32; F31; G12. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:957–988, 2003     

MANAGING VENDOR INVENTORY IN A DUAL LEVEL DISTRIBUTION SYSTEM

Collaborative arrangements among members of the supply chain have received a great deal of interest in recent years as a means of reducing costs. One such arrangement is vendor managed inventory (VMI). VMI allows the vendor to make decisions concerning the quantity and timing of deliveries to the retailer. Such an arrangement offers the potential of a more efficient supply chain by removing the negative effects of retail ordering policies. A thorough review of the literature was conducted to identify factors likely to impact the performance of a VMI partnership. Computer simulation was used to study the effects of these factors from both the vendor's and retailer's perspectives. The results lend insight into the performance of VMI and guidance for managers as to the environments in which VMI is most effective.     

AN EVALUATION OF PROCESS‐ORIENTED SUPPLY CHAIN MANAGEMENT FRAMEWORKS

Supply chain management (SCM) is implemented by integrating corporate functions using business processes within and across companies. Several process‐oriented frameworks for SCM have been proposed but only two of these provide sufficient detail to enable implementation. We evaluate the Supply‐Chain Operations Reference (SCOR) framework and The Global Supply Chain Forum (GSCF) framework using four criteria and identify their relative strengths and weaknesses.     

CRIME AND POVERTY: A SEARCH‐THEORETIC APPROACH*

Numerous studies document that criminal activity is positively related to unemployment and negatively related to educational attainment levels within given communities. We study this phenomenon in the context of a search‐equilibrium model, in which agents choose between formal employment and pursuing crime‐related activities (theft). Prior to their “occupational choices,” agents undertake costly schooling, raising their productivity. Crime acts, in essence, as a tax on human capital by affecting the probability that a worker's earnings (possessions) are subsequently appropriated. There are multiple equilibria. High crime, low levels of educational attainment, long spells of unemployment, and poverty are correlated across them.     

The Contingent Value of Responsive and Proactive Market Orientations for New Product Program Performance*

While the benefits of being market oriented are largely accepted, a group of scholars and managers remain skeptical. Marketing scholars have sought to counter the criticisms leveled against market orientation (MO) by arguing that it has both responsive and proactive dimensions. However, few studies have empirically examined the complexity of the effects of these dimensions on firm performance. Drawing on theories of resource‐based advantage and organizational search behavior, this article advances understanding by arguing that responsive and proactive market orientations have curvilinear effects on product development performance, that their interaction may be positively related to product development performance, and that their effects on new product program performance are moderated differentially by the organizational implementation conditions and marketing function power. Survey results of 175 U.S. firms indicate support for most of the hypotheses. Specifically, whereas responsive MO has a U‐shaped relationship with new product program performance, proactive MO has an inverted U‐shaped relationship with new product program performance. Contrary to the arguments presented here, the interaction of both orientations is negatively related to new product program performance. This study finds that both orientations are needed; however, new product program performance is enhanced when one is at higher level and the other is at lower level. Finally, responsive MO is only positively related to new product program performance under specific conditions such as when strategic consensus among managers is high. On the other hand, the positive effect of proactive MO on new product program performance is further strengthened when learning orientation and marketing power are high. Overall, this study suggests that the effects of responsive and proactive MO on new product program performance are more complex than previously theoretically argued and empirically examined.