电子商务安全管理的现状及其对策

本文把电子商务的安全分为法制安全、信息技术安全和企业内部管理安全，并分析了电子商务安全的现状，最后给出了通过加强法制建设实现法制管理；通过认证和识别、安全协议、加密技术、防火墙、网络病毒防治等技术手段实现信息技术安全管理；通过健全企业内部管理制度实现企业内部安全管理的建议对策。     

Are gold,USD, and Bitcoin hedge or safe haven against stock? The implication for risk management

This study investigates whether gold, USD, and Bitcoin are hedge and safe haven assets against stock and if they are useful in diversifying downside risk for international stock markets. We propose a combined GO-GARCH-EVT-copula approach to examine the hedge and safe haven properties of gold, USD, and Bitcoin. We then examine the attractiveness of these assets in reducing stock portfolio risk by using downside risk measures estimated by the proposed approach and other competing models. We also evaluate the relative performance of the proposed model in reducing downside risk with the competing models. The findings of the study indicate that the USD is the most valuable hedge and safe haven asset closely followed by gold, while Bitcoin is the least valuable. It is also observed that the proposed combined approach performs best in reducing the portfolio downside risk. The findings of this study are of significance for portfolio managers and individual investors who wish to protect the portfolio value during market turmoil.     

The Case of the Missing Pollution Haven Hypothesis

One particularly vexing puzzle for economists and policymakers over the past several decades concerns the empirical significance of the theoretically predicted pollution haven hypothesis. While neoclassical theory and conventional wisdom both surmise that local economies will suffer deleterious effects from stricter environmental regulations, empirical studies have largely failed to validate such claims. This study utilizes the method of matching to show that the impact of stricter regulation is heterogeneous spatially, varying systematically based on location-specific attributes. Previous studies that assume a homogenous response may therefore inadvertently mask the overall impact of more stringent regulations by pooling unaffected and affected regions.JEL Classification: Q25, Q28, H00, L51, R1The authors wish to thank to Michael Crew, Anthony Heyes, an anonymous referee, Werner Antweiler, Randy Becker, Wayne Gray, Shelby Gerking, Michael Greenstone, Vern Henderson, and Arik Levinson. Participants at various university seminars and conferences also lent useful insights to this line of research.     

Theory and practice of monetary policy

Summary. We consider an optimally managed renewable resource with stochastic non-concave growth function. We characterize the conditions under which the optimal policy leads to global extinction, global conservation and the existence of a safe standard of conservation. Our conditions are specified in terms of the economic and ecological primitives of the model: the biological growth function, the welfare function, the distribution of shocks and the discount rate. Our results indicate that, unlike deterministic models, extinction and conservation in stochastic models are not determined by a simple comparison of the growth rate and the discount rate; the welfare function plays an important role.Received: 20 October 2004, Revised: 28 February 2005, JEL Classification Numbers: D90, O11, O41, Q32.Santanu Roy: Correspondence toResearch on this paper was completed when the second author visited Cornell University in July, 2003. We thank the Center for Analytic Economics and the Department of Economics at Cornell University for making this research visit possible. The current version has gained considerably from the comments made by an anonymous referee.     

物流运输企业的车队管理

车队是物流运输公司中一个重要的职能部门,直接影响物流服务质量和物流成本。车队管理也一直是一个难点。文中从车队驾驶员、车辆、调度、安全四个方面入手,全面地分析了车队管理的方方面面。     

浅析国际直接投资自由化进程中的中国外资政策

随着全球经济一体化的演进，国际直接投资日趋自由化流动。国际直接投资自由化的兴起在全球经济的增长和国际分工深化的进程中发挥了越来越重要的作用。我国是利用国际直接投资的大国，目前正处于向市场经济转轨的关键时期，经济体制和市场结构还不完善，如何在确保国家经济安全的前提下，推进国际直接投资自由化进程，积极合理地扩大引资规模，应成为人们关注的焦点问题。因此，本文试图探寻国际直接投资自由化的经济机理，总结出国际投资自由化的有效制度安排对现行制度进行调整，以期更好地把握和指导我国改革开放实践及进一步融入国际直接投资自由化进程。     

How can investors build a better portfolio in small open economies? Evidence from Asia’s Four Little Dragons

This study investigates the role of hedging and portfolio design among stocks, exchange rates, and gold in small open economies (SOEs) from 4 January 2000 to 31 March 2020. We adopt the trivariate dynamic conditional correlation-fractionally integrated asymmetric power ARCH model and unconditional quantile regression model, and our findings show that the hedging role of the U.S. dollar (USD) and gold against stocks differs under regular and extreme market conditions. The USD can act as a powerful hedge asset for stocks in regular market periods. Moreover, during the global financial crisis and COVID-19 outbreak, the safe-haven effect of gold becomes stronger for almost all stocks, whereas the USD can serve as a strong safe haven against stock markets of Korea, Taiwan, and Singapore when stock returns are extremely low. In terms of portfolio designing, we find that adding the USD and gold to portfolios improves their hedging effectiveness, and the optimally weighted stock-USD-gold portfolio is the best portfolio strategy, irrespective of referring to return or risk.     

Scarcity of safe assets,inflation, and the policy trap

A goal of this paper is to make sense of the seemingly puzzling behavior of interest rates and inflation – and the role of central banks in that behavior – during and after the Great Recession, particularly in the United States. To this end, we construct a model in which government debt plays a key role in exchange, and can bear a liquidity premium. If asset market constraints bind, then there need not be deflation under an indefinite zero interest rate policy (ZIRP). Further, ZIRP may not be optimal under these circumstances. A Taylor-rule central banker could be subject to a ZIRP trap and persistently undershoot target inflation. As well, a liquidity premium on government debt creates additional Taylor rule perils, because of a persistently low real interest rate. We make a case that this is the key policy predicament currently faced by many central banks in the world.     

Government as borrower of first resort

Optimal government bond supply is examined under asymmetric information and safe asset scarcity. Corporations issue junk debt when demand for safe debt is high since uninformed investors then migrate to risky overheated debt markets. Uninformed demand stimulates informed speculation, driving debt prices toward fundamentals, encouraging pooling at high leverage. As borrower of first resort, government can issue bonds, siphoning off uninformed demand for risky corporate debt, reducing wasteful informed speculation. Government bonds eliminate pooling at high leverage or improve risk sharing in such equilibria. Optimal government bond supply is increasing in demand for safe assets and non-monotonic in marginal Q.     

环境规制与中国工业区域布局的“污染天堂”效应

借鉴Abay Mulatu和Reyer Gerlagh(2009)的研究,应用地区与产业特征交互作用的经典贸易模型,对中国区域间的污染天堂效应进行了测度。实证分析表明,在各省环境规制力度不同的条件下,污染密集型产业的布局从环境规制力度大的省份向环境规制力度小的省份转移;中西部地区的环境规制力度普遍弱于东部地区。因此,若不加以重视,中西部地区很可能会沦为东部污染密集型产业规避高环境规制的污染天堂,从而导致这些地区生态环境的恶化。