基于GARCH族模型对中国股市波动的分析与预测

运用GARCH类模型对沪深300指数序列的波动性、收益率进行了实证研究,并且对序列做了拟合与预测,获得了不错的效果。除此,还证实了中国股市存在着显著的非对称效应。     

居民消费价格指数ARCH族模型检验

居民消费价格指数(CPI)在一定程度上反映了通货膨胀或紧缩程度,往往成为各种研究关注的重点。应用GARCH类模型对月度CPI的波动性进行了建模.结果表明该模型能有效拟合月度CPI的波动性特征;并根据分析得出我国市场经济还不成熟。     

第三方仓储物流企业盈利模式探讨

文中主要论述了第三方仓储物流企业三大类共四种不同类型的盈利模式,包括空间仓储服务模式、增值服务模式和基于供需管理平台的服务模式,其中基于供需管理平台的服务模式可分为作为初级阶段管理增值模式和高级阶段的供需网控模式。文中最后还提出了模式转换的建议措施。认为,前两种模式是过去和当前第三方仓储物流企业的主要盈利模式,后两种模式则代表着企业未来的发展方向。     

An explanation for the price puzzle: Asymmetric information and expectation dynamics

Using theoretical and empirical analyses, this paper shows that the expectation dynamics induced by information asymmetry between the Central Bank (CB) and the public can cause the price puzzle. The signalling and learning dynamics between the CB and a representative private-sector agent under asymmetric information is investigated. Inflation positively reacts to contractionary monetary policy because the change in the interest rate is perceived as a signal of the CB’s private information about higher future inflation and output by the public. The empirical section of the paper validates this theoretical argument using a VAR specification about the US economy. Besides providing an explanation for the price puzzle, the results of this paper has practical implications about transparency and monetary policy. The theoretical and empirical findings indicate that asymmetric information causes significant frictions in the transmission mechanism of monetary policy. These frictions induce short-run undesired effects like increase in expected inflation and actual inflation as a response to contractionary monetary policy which is identified as “the price puzzle”.     

The economic impact of shale gas extraction: A review of existing studies

Recent advances in drilling technology have allowed for the profitable extraction of natural gas from deep underground shale rock formations. Several reports sponsored by the gas industry have estimated the economic effects of the shale gas extraction on incomes, employment, and tax revenues. None of these reports has been published in an economics journal and therefore have not been subjected to the peer review process. Yet these reports may be influential to the formation of public policy. This commentary provides written reviews of several studies purporting to estimate the economic impact of gas extraction from shale beds. Due to questionable assumptions, the economic impacts estimated in these reports are very likely overstated.     

Monetary and fiscal policy interactions in the post-war U.S.

A New Keynesian model allowing for an active monetary and passive fiscal policy (AMPF) regime and a passive monetary and active fiscal policy (PMAF) regime is estimated to fit various U.S. samples from 1955 to 2007. The results show that data in the pre-Volcker periods strongly prefer an AMPF regime, even with a prior centered in the PMAF region. The estimation, however, is not very informative about whether the Federal Reserve's reaction to inflation is greater than one in the pre-Volcker period, because much lower values can still preserve determinacy under passive fiscal policy. In addition, whether a PMAF regime can generate consumption growth following a government spending increase depends on the degree of price stickiness. An income tax cut can yield an unusual negative labor response if monetary policy aggressively stabilizes output growth.     

Comparing theories to explain e-commerce adoption

E-commerce is a strategy for rapid growth, especially by small and medium sized businesses (SMEs). However, the adoption rate of e-commerce by SMEs in Latin America is still undersized. The authors compare the theory of planned behavior (TPB) and the theory of reasoned action (TRA) using structural equation modeling to determine which is better at predicting e-commerce adoption intentions among 210 SME managers/owners in Chile. Contrary to previous research with American respondents, the study does not find significant differences between the two theories. Thus, academics should select the more parsimonious model (TRA) to study e-commerce adoption issues in developing countries.     

物流企业集群服务创新行为演化模型及案例分析

文章根据复杂系统理论观点,分析了物流企业集群服务创新系统的构成要素,及其行为演化的框架体系;基于复杂系统涌现机理,构建了物流企业集群服务创新行为演化的状态层级模型;最后以天津保税物流园区为例进行案例分析,剖析其创新演化过程,期望为天津以至我国物流企业集群的发展提供一定的借鉴。     

Extending the BG/NBD: A simple model of purchases and complaints

Extant customer-base models like the beta geometric/negative binomial distribution (BG/NBD) predict future purchasing based on customers' observed purchase history. We extend the BG/NBD by adding an important non-transactional element that also drives future purchases: complaint history. Our model retains several desirable properties of the BG/NBD: it can be implemented in readily available software, and estimation requires only customer-specific statistics, rather than detailed transaction-sequence data. The likelihood function is closed-form, and managerially relevant metrics are obtained by drawing from beta and gamma densities and transforming these draws to a sample average. Based on more than two years of individual-level data from a major U.S. internet and catalog retailer, our model with complaints outperforms both the original BG/NBD and a modified version. Even though complaints are rare and non-transactional events, they lead to different substantive insights about customer purchasing and drop-out: customers purchase faster but also drop out much faster. Furthermore, there is more heterogeneity in drop-out rates following a purchase than a complaint.