资源企业商业模式选择对产业结构的影响研究——以中国有色金属上游产业为例

文章选取30家企业作为样本,选取目标客户、竞争战略、产品形式、主要收入来源、组织结构、资源和能力为衡量商业模式的变量,以目标客户和竞争战略的差异将样本分为四类--Ⅰ类浙江有色地勘模式、Ⅱ类中金黄金模式、Ⅲ类金川集团模式、Ⅳ类湖南有色金属集团模式,分析了四类模式的优缺点.选取并分析了目标客户、竞争战略、内外部资源和能力三个变量对行业集中度、产品差异化和进入退出壁垒的影响.研究发现,未来资源产业中,产业链纵向整合程度将越来越高,企业将拥有从上游勘探开采直至下游精炼深加工的一体化产业链.     

A boosting approach to forecasting gold and silver returns: economic and statistical forecast evaluation

We use a boosting algorithm to forecast the returns of gold and silver prices. We then study the implications of using different information criteria to terminate the boosting algorithm in terms of the statistical and economic performance of a forecasting model. Our findings demonstrate that information criteria that select parsimonious forecasting models perform better in statistical terms than information criteria that select relatively complex forecasting models, but this good performance does not necessarily survive an economic performance evaluation.     

Non-linear volatility dynamics and risk management of precious metals

In this paper, we investigate the value-at-risk predictions of four major precious metals (gold, silver, platinum, and palladium) with non-linear long memory volatility models, namely FIGARCH, FIAPARCH and HYGARCH, under normal and Student-t innovations’ distributions. For these analyses, we consider both long and short trading positions. Overall, our results reveal that long memory volatility models under Student-t distribution perform well in forecasting a one-day-ahead VaR for both long and short positions. In addition, we find that FIAPARCH model with Student-t distribution, which jointly captures long memory and asymmetry, as well as fat-tails, outperforms other models in VaR forecasting. Our results have potential implications for portfolio managers, producers, and policy makers.     

Downside risk in Dow Jones Islamic equity indices: Precious metals and portfolio diversification before and after the COVID-19 bear market

Besides great turmoil in financial markets, the COVID-19 pandemic also disrupted the global supply chain, putting the precious metal market into great uncertainty. In this study, we revisit the diversifying role of precious metals – gold, silver, and platinum – for six Dow Jones Islamic (DJI) equity index portfolios using a battery of tests: dynamic conditional correlations (DCCs), four-moment modified value at risk (VaR) and conditional VaR, and global minimum-variance (GMV) portfolio approach. Our empirical results exhibit drastically increased DCCs between sample assets during the COVID period; however, pairing gold with any of the DJI equity indices (except for the Asia-Pacific region) decreases the downside risk of these portfolios. Other precious metals (silver and platinum) do not provide such benefits. Furthermore, we find that a higher allocation of wealth in DJI Japanese equities and gold is required to achieve a GMV portfolio in the post-COVID-19 era, implying higher transaction (hedging) costs to rebalance portfolios (weights) accordingly. Our out-of-sample tests examining the global financial crisis, European debt crisis, and extended sample (2000–2020) periods yield similar findings as gold glitters across all market conditions. Overall, our findings provide notable practical implications for both domestic and international investors.     

西安副中心区土壤重金属污染特征与健康风险研究

随着中心城区的工业、人口向副中心地区疏散，快速城市化和工业化的释放物在该地区的土壤环境中不断累积。以西安市副中心鄠邑区为例，采用污染评价和风险分析模型研究其表层土壤中V、Cr、Mn、Co、Ni、Cu、Zn、As、Pb、Ba的累积状况。结果表明，研究区土壤已经受到轻微的重金属累积污染，Pb、Zn、Cr、Cu、Ba的累积较重。Cr、Ba的累积较西安市中心区丰富，Zn的累积处于中心两个对比区域之间，Cu、Pb、Mn、Ni、As、Co、V的累积则弱于西安市中心区；地累积指数和富集因子的评价结果在平均污染水平定级和各污染程度样品数所占比例上相似；当前这些重金属还未引起非致癌性和致癌性健康风险，Cr、As、Mn、V、Pb、Ba产生非致癌风险的可能性较大。     

The role of global economic conditions in forecasting gold market volatility: Evidence from a GARCH-MIDAS approach

In this study, we examine the role of global economic conditions in the predictability of gold market volatility using alternative measures. Based on the available data frequency for the relevant series, we adopt the GARCH-MIDAS approach which allows for mixed-data frequencies. We find that global economic conditions contribute significantly to gold market volatility, albeit with mixed outcomes. While the results also lend support to the safe-haven properties of the gold market, the outcome can be influenced by the choice of measure for global economic conditions. For completeness, we extend the analyses to other precious metals (palladium, platinum, rhodium and silver) and find that the global economic conditions forecast the return volatility of the gold market better than these other precious metals. Our results are robust to multiple forecast horizons and offer useful insights on the plausible investment choices in the precious metals market.     

浅析产业集群与提高湖南有色金属工业国际竞争力

文章论述了产业集群在经济发展中的重要作用，从产业集群有利于集群内企业生产率和社会资源配置效率的提高、会带来经济发展的低成本优势、实现规模经济效应、具有技术制度创新优势等方面阐明了产业集群与区域经济发展的关系。并指出发展湖南有色金属产业集群，提高湖南有色金属工业国际竞争力的具体措施。     

Diamonds and precious metals for reduction of portfolio tail risk

ABSTRACT

We study the performance of diamonds compared to gold and other precious metals in mitigating the tail risk of a diversified equity market portfolio over the period June 2007 to October 2018. Our results display a diversification benefit of some diamond indices, which also improve the portfolio reward-to-risk ratio. To corroborate this evidence, we study the dependence structure and tail dependence of diamonds and a broad equity market portfolio and compare it to the dependence obtained with gold and other precious metals. Results from fitting a bivariate copula show that the average left tail dependence reaches its minimum when diamonds are used. We also show that using shares of diamond-mining companies does not provide the same benefits.     

湖南省有色金属工业场地时空演变及其预测

通过收集大量湖南省有色金属工业场地的最新数据,从省级尺度进行分析,反映有色金属行业演变历程,为未来产业布局提供参考。以湖南省有色金属工业场地为研究对象,通过核密度分析方法和多变量自回归模型,揭示其时空分布规律,并预测其未来发展状况。研究结果表明：①1990—2019年有色金属工业场地数量明显增加,形成了以郴州为“核心集聚区”,多城市为“次核心集聚区”,并从集聚区中心不断向边缘扩散的空间演化格局;②多变量自回归模型能够很好地表达主控因子与场地数量的时序关联,模拟精度较高;③模型预测显示,在经济社会持续稳定发展的情景下,2020—2025年湖南省各市州有色金属工业场地的数量呈增长趋势,郴州、衡阳的采选和冶炼场地的增量和数量均较大,湘西的采选场地增量和数量较大,益阳、娄底的冶炼场地增量和数量较大。研究思路及方法对大区域范围内的工业或第三产业运营场所数量或规模的时空模拟及预测有借鉴意义。     

The World Production and Trade of Rare Earth Elements： The Position of the Pacific Area

In this paper we analyze the characteristics of the so-called rare earth elements （REEs） and its industrial applications. We present the policy, or lack thereof, in the countries in the Pacific Rim for its mining and commerce, and the current and future weight that rare earth minerals will have in international trade. The technological revolution experienced over the last 25 years, has brought the REEs to the public＇s attention for being instrumental in obtaining catalysts, lasers and optical fiber, luminescent substances and LEDs, superconductors, permanent magnets, batteries and ultra-capacitors. China＇s leading position as the supplier of these minerals worldwide, and its recent export restriction policy for domestic industrial activities have driven up international prices. Price increase for REEs is leading to the need for both recycling and its replacement. It has also led other countries in the Asia Pacific Rim to prospect new potential sites on their own territories, or even to restart operations in deposits that had been previously abandoned. Those strategies will likely gain greater importance as environmental pollution problems associated with the exploitation, processing, and recovery of REEs increase.