Economic implications of maintaining rangeland ecosystem health in a semi-arid savanna

A simulation model was used to determine the ecological and economic consequences of managing stocking rate on semi-arid savanna rangeland continuously stocked with livestock to achieve the alternate management goals: (1) maintaining current range condition, (2) maximizing profit, or (3) improving range condition over a 30-year time frame. We developed values for end of the year herbaceous standing crop and utilization required to attain these management goals for rangeland in poor to excellent condition. Based on extensive field research conducted in this region over 5 decades, range condition in this model is programmed to decline in response to three factors: excessive grazing pressure, below average precipitation, and an increase in woody plants. Earning capacity is four times higher for range in excellent condition than that in poor condition. For all initial range condition (RC) values, simulated stocking rates that maintained RC resulted in simulated mean weaning weights 93-94% of maximum. Maximum short-term and long-term profit is attained at higher stocking rates than would maintain long-term range condition and at much higher levels than would increase range condition levels. When stocked for maximum profit, individual animal performance was 90% of maximum. The model predicts that low stocking rates allow range condition to improve. At these recovery stocking rates, total 30-year profits were found to be 78%-87% of the stocking rates that would maintain range condition, and only 67%-75% of stocking rates that would maximize profit. Predictions of the end of year standing crop to maintain range condition were in broad agreement with the 1000 kg ha^− 1 advised for this region. To improve range condition, the model predicts that an end of year standing crop of 1500-2000 kg ha^− 1 is required, compared to the generally advised level of 1200-1500 kg ha^− 1. The predicted end of year forage standing crops for the maximum profit goal are well below the advised 800 kg ha^− 1 threshold required to prevent degradation for all of the initial range conditions that were simulated. To ensure maintenance of range in excellent condition, our results concur with the advised utilization levels of 20-25%. However, for range in poorer than excellent condition, the model predicted much lower utilization levels were needed to maintain or improve range condition.     

基于马歇尔—勒纳条件的中国茶叶贸易收支研究

马歇尔—勒纳条件是分析汇率变动对贸易收支影响的重要理论。本文采用我国1986～2008年茶叶进出口的序列数据,通过分析我国对不同经济体的茶叶进出口需求弹性,并构建实际有效汇率等因素与茶叶贸易收支的计量模型,研究了我国茶叶进出口与马歇尔—勒纳条件间的满足关系。研究表明,我国与不同国家的茶叶贸易收支受汇率变动的影响不同;就我国茶叶对外贸易总体而言,茶叶进口价格下降会增加进口额,出口价格上升会增加出口额;而人民币升值会改善我国茶叶贸易收支,人民币贬值会恶化我国茶叶贸易收支,且进出口需求弹性之和小于1。因此,我国茶叶贸易收支反向符合马歇尔—勒纳条件,这为汇率波动背景下科学处理茶叶贸易问题提供了重要的理论指导。     

International competition and wage differentials - the case of Taiwan

This paper documents and investigates the structure of relative wages among skill groups (distinguished by gender, education and potential experience) in Taiwan over the period 1978 to 1990. To account for these changes, I construct a model of wage determination in which demographic groups are treated as separate inputs into the production process. Thus, the changes in relative wages are determined by (i) changes in the relative supply of input factors; (ii) changes in the product composition; and (iii) biased technical changes that shift the relative demand for inputs. Analysis of OECD trade statistics shows that manufacturing imports from Taiwan to OECD, the main source of derived demand for the unskilled labour, exhibited a time pattern that matches the overall relative demand shifts.     

人民币实际有效汇率的分解和马歇尔—勒纳条件的修正

马歇尔-勒纳条件是探讨货币贬值改善贸易收支的规律,本文根据人民币实际有效汇率的特点,把它分解为美元有效汇率和人民币对美元汇率之积形式,在此基础之上,本文重新考察货币贬值改善贸易收支的条件,对传统的马歇尔-勒纳条件进行修正。从我们研究中可以看出美元实际有效汇率变化对马歇尔-勒纳条件修正的重要作用,这包括美元有效汇率对人民币汇率弹性和人民币在美元有效汇率中的权重的两种影响。另一方面,即使人民币实际有效汇率贬值存在“J”曲线效应,人民币对美元实际汇率贬值,“J”曲线是否存在还要依赖一定的条件。本文实证研究结果显示出口（或进口）与人民币对美元实际汇率、美元实际有效汇率指数和外国收入（或国内收入）之间存在着显著的协整关系,美元实际有效汇率和人民币对美元实际汇率也存在显著的协整关系。从弹性的变化来看,修正的马歇尔-勒纳条件成立,同时人民币对美元实际汇率贬值有利于改善贸易收支,美元实际有效汇率贬值会恶化中国贸易收支。而对“J”曲线效应的实证研究显示无论是人民币实际有效汇率,还是人民币对美元实际汇率贬值和美元实际有效汇率贬值,我国“J”曲线效应均不显著。     

京津冀经济圈农民工医疗与健康状况评估体系研究

为科学评估农民工医疗与健康状况,选取能代表京津冀经济圈农民工医疗与健康状况的指标,构建出一个力求合理、科学、简明、可行的京津冀经济圈农民工医疗与健康状况评估指标体系,作为评估京津冀经济圈乃至全国农民工群体医疗与健康状况的依据和工具。     

企业经营者职业化的条件、作用及最终路径

经营者的职业化是现代企业制度的必然要求.它需要建立三项基本制度,即职业证书制度、职业经理评级制度和市场化聘任与解聘制度;需要三个基本条件即要有理性的买者、充裕的卖方和规范的中介机构;职业化的路径是体制外经理市场压迫体制内经理市场,最终导致二者并轨.     

知识隐藏的发展逻辑：一个文献综述

知识隐藏是一种由特定前因变量触发并对员工工作行为、团队绩效和组织长期发展构成威胁的知识行为。鉴于此,依托“触发条件—影响机制—弱化机理”分析框架,以知识隐藏国内外文献为研究对象,运用文献计量与归纳相结合的研究方法,界定知识隐藏概念并厘清知识隐藏测量手段及其维度,从员工个体、组织情境、知识特性3个视角对知识隐藏触发条件进行梳理,揭示知识隐藏对个体工作、任务和组织绩效的影响机制,阐述现有国内外文献对知识隐藏弱化机理的研究并对国内知识隐藏研究提出5条发展路径,对于深入研究知识隐藏相关理论具有一定借鉴意义。     

论税收代位权行使的条件及其法律效果

新《税收征收管理法》借鉴外国税收立法的经验，将我国《合同法》所构建的代位权制度应用到税收领域，从而创设了税收代位权制度。税收代位权制度是将民事制度引入公法领域的有益尝试，不仅可以弥补税务机关行政权力行使在他人责任方面的不足，而且在立法层面上肯定了“税收债务关系”。为保证各种税收制度的协调，必须合理界定税收代位权的行使条件。由于税收代位权体现着社会公益性，逻辑上必然要求其法律效果采用“优先规则”。     

苏洵的管理学思想论析

苏洵擅长政论,重视经世致用,他的文章多为纵论国家大事,为当时帝王治理国家出谋划策.去除其封建性的因素,苏洵的思想具有丰富的管理学内容,值得我们借鉴.苏洵在经营策划、应用权术、人才选用、奖励制度、甄别奸邪等方面的意见足资我们参考取用.     

国家金融安全的杠杆──发展中国家汇率制度的选择

世界金融一体化已成为二十一世纪主要经济特征,并强烈的影响着发展中国家的金融政策,关乎国家金融安全,而选择适当的汇率制度则是解决这一问题的杠杆。本文从时间和空间两个角度出发,历史地比较地分析了发展中国家汇率制度的选择要素、内在结构及其战略取向。