生猪价格的省域空间溢出效应及其动态关联分析——基于空间面板模型和DY分解

目的 分析生猪价格的省际空间溢出效应,并通过各省域间价格联动效应探究我国生猪价格体系的传导机制,对治理我国生猪产业区域不均衡发展问题具有重要意义。方法 文章建立空间杜宾模型探索生猪价格的空间传导特性,引入溢出效应分解分析替代品价格、成本要素对省域生猪价格的冲击效应,并运用广义预测误差分解测定省际生猪价格关联水平及方向。结果 （1）我国生猪价格波动具有显著空间相关性和异质性,其空间集聚特征随时间推移愈发显著,产业布局呈现“高—高南部簇拥,低—低东向西扩”的空间演变特征。（2）省内替代品价格、成本要素对生猪价格波动的影响显著但作用力度有限,省际溢出效应是生猪价格发生空间传导的主导因素。（3）鸡肉价格与省内、省外的生猪价格存在密切正向关联;牛肉价格波动推动本省生猪价格同步波动;豆粕价格波动对本省或邻省生猪价格均起到正向推动作用;玉米价格变化引起本省或邻省生猪价格的负向变化。（4）辽宁、河北、吉林、河南等省的正向净关联度较大,属于波动“主导者”或“发动者”;上海、广西、重庆等省市的负净关联度较大,隶属价格波动的“接收者”;江苏、湖南、福建等省市的关联度和全国平均关联度持平,在价格波动传导体系中属于波动“中介者”。结论 有关部门应针对不同省域在生猪价格传导体系中所发挥职能的不同,分级管控生猪价格,同时促进地方畜牧业经济发展,不断优化我国生猪养殖产业区域布局。     

Measuring real–financial connectedness in the U.S. economy

We analyze the connectedness between the real and the financial sectors of the U.S. economy. Using the weekly ADS index of the Philadelphia Fed (the widely used business conditions indicator) to represent the real side, we find that during times of financial distress and business cycle turning points, the direction of connectedness runs from the real sector to financial markets. The ADS index is derived from a model containing a measure of term structure along with real variables. Therefore, it might not be the best representative of the real activity used in the connectedness analysis. As an alternative, we derive a real activity index (RAI) from a dynamic factor model of the real sector variables only. The behavior of RAI over time is quite similar to that of the ADS index. When we include RAI to represent the real side, connectedness from the real side to financial markets weakens substantially, while the connectedness from financial markets to the real side becomes more pronounced.     

Past managerial guidance and returns to variance trading around earnings announcements

I investigate the relationship between past managerial guidance and realized variance risk premiums (VRPs) – i.e., the difference between implied and realized variance – in equity options around earnings announcements. I find that implied variances are lower before earnings announcements but VRPs are higher when firms provide guidance. I also find higher option-implied jump risk when firms issue surprising guidance. Further tests suggest a portion of the higher VRPs are due to changes in perceived higher-order risks, but traders also underreact to the precision of information in short-term guidance. These results are attenuated for firms with a better information environment.     

中国场内期权市场研究——基于中美关于期权隐含方差的差异

本文对比了美国和中国关于期权隐含方差的两个典型理论规律所表现出的实证差异。首先,期权隐含方差作为公认的风险度量指标,应该与未来期间的股权溢价成正相关关系,在这一点上中美实证结果完全相反;其次,现代期权定价理论预测期权隐含方差应该高于标的资产实现方差,而中国市场期权隐含方差和实现方差的比值要显著低于美国。     

The Investment Opportunity Set and Capitalization versus Expensing Methods of Accounting Choice

This paper examines the effects of the investment opportunity set (IOS) on management's decision to capitalize or expense significant costs in two diverse settings: (1) in accounting for exploration and development (E&D) costs by firms in the oil-and-gas industry, and (2) in accounting for research and development (R&D) costs by firms (across industries) prior to 1974. We argue that the relation between the IOS and the decision to capitalize versus to expense is based upon managerial incentives to reduce the variance of accounting earnings. High-growth firms are more likely to have more variable earnings, which therefore creates greater incentives to reduce earnings variability. Because the capitalization method generally results in a lower variance of reported earnings than does the expensing method, high-growth firms are more likely to select capitalization. Our results show that, after controlling for firm size and for the indirect effects of the IOS mediated by debt contracts, high-growth firms (firms with fewer assets-in-place) are more likely than low-growth firms to select the capitalization method of accounting for E&D and R&D expenses.
JEL classification: M41; G31     

中国经济增长动力的需求分析

本文运用向量协整与误差修正模型，从需求的角度对近年来影响中国经济增长的几个重要因素进行了实证分析。美国GDP、中国出口及房地产开发投资每增长1个百分点，将分别拉动中国GDP增长0．87、0．15和0．16个百分点。方差分解分析的结果表明，在中国GDP的变动中，短期内自身扰动项及房地产开发投资扰动项的冲击将起主要作用，长期内美国GDP扰动项及出口扰动项的冲击将起主要作用。为保持中国经济健康稳定增长，在经济政策制定或宏观调控政策选择时，要充分考虑这些变量冲击对经济增长的不同影响时限和影响力度。     

江西省农民收入结构及地区差异分析

随着我国经济的飞速发展,农民收入差距也在不断扩大。由于受客观环境和地理位置等因素的影响,农业生产总体水平不同,农民收入构成中,转移性收入和财产性收入所占比重低,地区差异不显著,差异突出体现在工资性收入和家庭经营性收入上。要从根本上解决农民增收问题,不仅要改革传统的农业生产方式,而且关键是要把农业剩余劳动力由农业转移到非农业部门就业,这样才能产生良好效应。     

Stock index futures hedging in the emerging Malaysian market

The paper investigates hedging effectiveness of dynamic and constant models in the emerging market of Malaysia where trading information is not readily available and market liquidity is lower compared to the developed equity markets. Using daily data from December 1995 to April 2001 and bivariate GARCH(1,1) and TGARCH models, the paper uses differing variance–covariance structures to obtain hedging ratios. Performance of models is compared in terms of variance reduction and expected utility levels for the full sample period as well as the three sub-periods which encompass the Asian financial crisis and introduction of new capital control measures in Malaysia. Findings show that rankings of the hedging models change for the in-sample period depending on evaluation criteria used. TGARCH based models provide better hedging performance but only in the period of higher information asymmetry following the imposition of capital controls in Malaysia. Overall, despite the structural breaks caused by the Asian financial crisis and new capital control regulations, out of sample hedging performance of dynamic GARCH models in the Malaysian emerging market is as good as the one reported for the highly developed markets in the previous literature. The findings suggest that changes in the composition of market agents caused by large scale retreat of foreign investors following the imposition of capital control regulations do not seem to have any material impact on the volatility characteristics of the Malaysian emerging market.     

关于比率估计除偏及方差问题的探讨

比率估计是利用辅助资料进行抽样估计的一种最简单、最有产的方法之一。在一些书籍中,认为比率估计存在不可校正的偏差,而且将方差与均方误相混淆,提出了不准确的方差公式。其实比率估计可以通过除偏得到无偏估计量,并且方差公式也应进行修正。     

User Reviews Variance,Critic Reviews Variance,and Product Sales: An Exploration of Customer Breadth and Depth Effects

Online user reviews constitute a new element of the marketing communication mix that can significantly affect product sales. A general consensus holds that positive user reviews valence benefits product sales, yet the effect of variance is less intuitive and current findings are mixed. We propose that user reviews variance actually constitutes a double-edged sword that can either hurt or help product sales, depending on the variance of critic reviews and other quality signals. Three complementary studies in multiple industries (movies, digital cameras, and books) with multiple methods (secondary data analysis and behavioral experiment) reveal three key insights in this setting. First, after recognizing a high variance in user reviews, many potential buyers may simply exclude the focal product from their consideration sets for fear that it does not match their needs and preferences, which is termed the customer breadth effect. Second, high user reviews variance, in combination with high critic reviews variance, can elicit a sense of uniqueness and thus enhance purchase intentions of some consumers, which is termed the customer depth effect. Third, quality signals (e.g., product cost and product extension) can strengthen the positive customer depth effect. The overall effects of user reviews variance, therefore, can be negative, insignificant, or even positive. These findings have important theoretical and managerial implications.