随机折现因子方法与CAPM关于风险溢价的实证比较

本文根据随机折现因子方法的基本理论,结合广义矩阵法和蒙特卡罗模拟,对随机折现因子方法和传统的CAPM对风险溢价的计算进行实证比较研究。实证结果表明,对于中小样本,随机折现因子方法比传统的CAPM方法优越。估计量较为精确,误差小;对于大容量样本,这两种方法性能接近。另外,随机折现因子方法得到Jensen＇sα均值比CAPM方法得到Jensen＇sα均值小,而且标准偏差明显较小,也从另一角度说明了随机折现因子方法的优越性。     

Impact of land fragmentation and resource ownership on productivity and efficiency: The case of rice producers in Bangladesh

The paper analyzes the impact of land fragmentation and ownership of resources on productivity and technical efficiency in rice production in Bangladesh using farm level survey data. Results reveal that land fragmentation has a significant detrimental effect on productivity and efficiency as expected. The elasticity estimates of land fragmentation reveal that a 1% increase in land fragmentation reduces rice output by 0.05% and efficiency by 0.03%. On the other hand, ownership of key resources (land, family labour, and draft animals) significantly increases efficiency. The mean elasticity estimates reveal that a 1% increase in family labour and owned draft animal improve technical efficiency by 0.04% and 0.03%, respectively. Also, a 1% increase in the adoption of modern technology improves efficiency by 0.04%. The mean technical efficiency in rice production is estimated at 0.91 indicating little scope to improve rice production per se using existing varieties. Policy implications include addressing structural causes of land fragmentation (e.g., law of inheritance and political economy of agrarian structure), building of physical capital (e.g., land and livestock resources), improvements in extension services and adoption of modern rice technology.     

Asset prices in affine real business cycle models

I describe a tractable way to study macroeconomic quantities and asset prices in a large class of dynamic stochastic general equilibrium models. The proposed approximate solution is analytical, log-linear, and adjusted for risk. Therefore, it is well suited to investigate economic mechanisms, describe the time series properties or estimate the model, and deal with stochastic volatility. I explain the pitfalls encountered by previous attempts to use simple approximation techniques, in particular with models featuring recursive preferences. Finally, I show the theoretical relationship between my solution and higher-order perturbation methods.     

中国地区工业的生态效率测度及趋同分析：2003—2010年

生态效率兼顾经济活动的生态效益和经济效益,在一定程度上反映了经济可持续发展水平,其综合评价有助于探索经济发展方式转变的路径。2003—2010年中国大陆31个省份的工业生态效率测度及趋同分析表明：我国工业生态效率普遍偏低,其省际差异和年际变化差异都较大,而且存在明显的生态效率趋同。为进一步改善我国各省的工业生态效率,既要广泛搭建技术转移平台以促进先进技术推广,还要大力提高落后地区的技术能力以促进先进技术的充分吸收和利用。     

Forest management under fire risk when forest carbon sequestration has value

We develop a multiple forest use model to determine the optimal harvest date for a forest stand producing both timber and carbon benefits under a risk of fire. An empirical application is provided for a forest owner producing maritime pine in Southwest of France. Our results indicate that a higher risk of fire will decrease the optimal rotation period. On the contrary, higher carbon prices increase the optimal harvesting age. To investigate the contradictory effects of fire risk and carbon price on forest rotation, we identify the set of carbon prices and fire risks that lead to a given rotation age. We also show that forest owner's willingness to pay for a risk reduction can be substantial (37.33 euros by ha and by year to reduce the annual fire risk from 1.26% to 0.07%).     

Off‐farm work,technical efficiency,and rice production risk in Taiwan

This article investigates the differences in yield production, production efficiency, and yield risk for farmers both with and without off‐farm work. Using a nationwide survey of rice farmers in Taiwan, we estimate two stochastic production frontier models that accommodate technical inefficiency and production risk simultaneously for farmers both with and without off‐farm work. The stochastic dominance criterion is then applied to compare the differences in the distributions of the estimated technical efficiency and yield risk between groups. The empirical results indicate that these two groups of farmers use resources in different ways, and off‐farm work is not necessarily associated with lower technical efficiency. For farmers in the lower percentiles of the efficiency distribution, those with off‐farm work are more efficient than their counterparts without off‐farm work. In addition, farmers with off‐farm work face higher production risk and this result is robust for the entire distribution.     

Top pay transparency in Europe: codes,convergence and clichés

Following the waves of corporate scandals and the increasing attention to corporate governance, the transparency of reporting on director-level pay has increased across Europe. This article examines the extent of convergence in laws, codes and corporate reporting practices in regard to director-level pay in France, Germany, Switzerland and the UK. The paper analyses annual reports and the websites of 23 companies, using institutional theory to discuss the coercive, normative and mimetic pressures for convergence that are revealed, not just in the laws and codes in each country, but also in the standardized wording in the relevant sections of reports which have become clichés.     

International mergers and acquisitions in the UK 1985-94: a comparison of national HRM practices

The paper investigates HRM practices adopted by companies from the USA, Japan, Germany and France in UK companies that they have acquired. UK/UK acquisitions are used as a control. The research is based on a survey instrument applied to 201 companies and interviews with forty. It notes that there is some convergence of HRM practices, in that, for example, all countries researched employ performance-related pay and increase the amount of training in their new subsidiaries. It finds, however, that there is a distinct difference in the HRM practices employed by companies from each of the countries, influenced by the characteristic HR practices common to companies in the country of origin of the parent.     

基于随机过程理论的复杂可修系统可靠性规律研究

利用随机过程理论研究了复杂可修系统的可靠性规律,用随机过程模型中的Ｗｅｉｂｕｌｌ过程来描述复杂可修系统的可靠性规律。用Ｍｏｎｔｅ Ｃａｒｌｏ方法模拟验证了Ｗｅｉｂｕｌｌ过程模型的参数估计公式。其中参数β的最大似然估计误差低于２％,λ的最大似然估计误差低于７％。两组试验数据的处理结果表明Ｗｅｉｂｕｌｌ过程模型有较高的拟合精度。