禽流感危机下肉鸡产业市场状态分析*——基于互联网大数据和MS-VAR模型

[目的]为了有效应对禽流感冲击、维持肉鸡产业稳定健康发展。[方法]基于互联网大数据构建了禽流感舆情指数,选取2012年1月至2017年3月周度数据,通过MS-VAR模型分析了禽流感危机下肉鸡市场状态的转换特征以及不同市场状态下产业链价格传导关系。[结果]2012年以来可将肉鸡产业市场状态划分为危机状态和正常状态,肉鸡产业市场在两个市场状态下转换频繁;肉鸡产业危机市场状态和正常市场状态平均持续期分别为4.65周和9.05周;肉鸡市场在区制转移概率上存在明显的非对称特征;肉雏鸡、活鸡和白条鸡价格之间在危机状态下相关性小于正常市场状态下相关性;不同市场状态下肉鸡产业链价格传导存在差异;肉鸡产业市场在危机状态下不稳定程度明显增加。[结论]提出了加大对禽流感疫情的监测以及疫情处理能力,密切关注公众禽流感舆情动态变动情况,做好舆情引导,加强禽流感疫情科学知识的宣传,增强公众对禽流感的认知等对策建议。     

我国大麦价格波动特征及其影响因素分析

[目的]大麦价格剧烈波动会直接影响大麦种植户的生产积极性和大麦产业的平稳发展,研究大麦价格波动特征及其影响因素,有助于提升大麦产业链相关主体识别和应对市场风险的能力,促进大麦产业的健康发展。[方法]文章先采用HP滤波法和ARCH类模型分析了2011年4月至2017年2月我国大麦价格波动特征,然后采用脉冲响应函数分析了我国大麦价格波动影响因素。[结果]我国大麦价格波动存在明显的季节性和周期性,样本期内总体上呈现逐渐下降趋势;我国大麦价格具有显著的波动集聚性,我国大麦价格具有显著的不对称性;在该文选择的影响因素中,大麦进口量和国际大麦价格是影响我国大麦价格波动的主要因素。[结论]该文提出必须保障并提高国内大麦合理产能、完善大麦价格监测预警体系、加强国内大麦进口企业整合和推动大麦进口来源多元化的政策建议。     

中国制造业贸易模式变迁的工资差距效应

本文利用中国制造业27个细分行业的面板数据,采用固定效应不变系数的静态面板模型,考察了我国制造业从产业间贸易向产业内贸易的变迁对行业间工资差距的影响及其传导机制。研究结果表明：（1）在制造业贸易模式的变迁中,出口扩大了行业间工资差距,而进口缩小了行业间工资差距。（2）制造业贸易模式变迁主要通过价格机制扩大了行业间的工资差距,而技术机制和个体机制的影响则不显著。     

U.S. Canned Tuna Supply and Demand

Abstract

A 3SLS econometric model is used to estimate price elasticities of supply and demand for domestically produced and imported canned tuna in the U.S. market. In addition, a VAR model is developed to examine the relations between imports and domestically produced canned tuna. For domestically produced canned tuna, a 3SLS estimation of a structural econometric model yielded a coefficient for price elasticity of supply of 0.2 and of own-price demand of ?0.3. Such price inelasticities are expected of a fishery exploited at or near its maximum yields (inelastic supply), and a consumer product widely viewed as almost a necessity in a well-stocked pantry (inelastic demand). In addition, the model yielded a cross-price elasticity of demand with respect to the price of imported canned tuna of 0.45. Additional results include an income elasticity U.S. demand for domestically packed tuna of 0.83; a cross-price elasticity with the price of bread (a complement) of ?0.33, a cross-price elasticity for the price of ground meat (a substitute) of 0.30. With respect to imported canned tuna in the U.S. market, the corresponding elasticities estimated in the model are ?1.3 (own-price demand), 3.5 (income elasticity), ?1.2 (cross-price with the price of bread) and 2.5 (cross-price with the price of ground meat).

For canned tuna company managers, the results provide useful information about the likely effects on sales that would come from their own price changes, from changes in the price of imported canned tuna, and from price changes in the markets for complementary and substitute products. They can also use our results in discussions with U.S. trade negotiators, who are frequently faced with disputes over tariffs, market access, and other trade issues.     

Fees for Reefs: Economic Instruments to Protect Mexico’s Marine Natural Areas

Stated preference methods can be used to estimate the demand function where no price variation has been observed before. This is the situation of the Mexican coral reef natural protected areas, where after the 2002 approval of a $20 pesos fee (US$1.80) the Ministry of the Environment is now considering increasing the amount of the fee, not only to raise more revenue for the park, but also to curb the number of visitors in the cases where there is excess demand. There are concerns that the very success of the reefs is bringing associated environmental damage that threatens its sustainable use. To estimate the reaction of visitors to different fee levels, we carried out a contingent valuation survey, and constructed with its results an aggregate demand for each park. This demand was then divided by seasons and nationalities, to explore the benefits and costs of differentiating fees, looking at both the revenue maximising and the welfare maximising fees. Finally we discuss how these fees would change when environmental damage functions are taken into account. The recommendation is that increasing fees up to the point where they cover both private and environmental costs would bring the highest amount of economic benefit compatible with the sustainable use of these complex and wondrous marine ecosystems.     

中国农民增收困境的形成机制研究

中国农民收入问题必须通过与城镇居民收入差距的比较进行研究.解决农民增收问题的关键是通过政府的惠农政策不断提高农民人均纯收入的增长率.通过理论模型的分析,可以得出农民人均纯收入的增长率是由农产品价格的上涨率、技术进步率、人均资本的增长率和农业人口的转移率等四大因素决定.所以,提高农民收入的关键在于深化价格政策改革、促进科技兴农政策改革、改善金融投资环境和加快农村劳动力转移.     

平面任意力系的平衡方程及应用——高职教学中一道典型的例题

平面任意力系的平衡方程及应用是教学的重点和难点,它是解决物体系统平衡问题的基础,学生应理解并熟练掌握。本文举一典型例题来说明平面任意力系的平衡方程的三种形式的具体运用。     

城市地价空间自相关分析——以宿州市为例

运用全局和局域自相关统计量及地统计学半变异函数分析方法,对宿州市商业和住宅地价的全局自相关、各项异性及局域自相关特征进行了全面分析.结果表明:在2 800m范围内,宿州市商业和住宅地价均存在较强的正自相关性且趋于高值集聚,随着相关距离的增大,地价半方差按球状模型曲线增长,自相关性逐渐减弱;在不同方向上,地价的空间自相关特征不尽相同,南北方向上的空间自相关范围要大于东西方向,但随机性较强,自相关程度较东西方向弱;在全局呈显著自相关的情形下局域地价也主要呈空间集聚格局,但部分地区表现出异质性.     

经济评价中“决策油价”确定方法的探讨

原油销售价格是油田开发项目必须及石油石化项目经济评价应采用的重在参数之一,但随着我国与国际原料市场的接轨,近年来原油价格变化非常大,油田开发项目的建设周期又比较长,原油价格常常具有可变性,如何利用该参数进行项目经济评价是摆在我们面前的一个重要课题。引入“决策油价”的概念,并根据对世界的油价史和油价影响因素的分析,结合油介变化动态,确定“决策油价”进行经济评价工作,对冀对进一步开展该类项目的经济评价工作起到参考作用。     

房地产住宅价格影响因素的实证分析——以沈阳市为例

住宅价格是房地产市场的晴雨表,能够反应房地产市场的供需情况,以及政策的影响。本文通过对沈阳市住宅价格影响因素进行分析,确立研究指标,并借助沈阳市2002年到2011年统计数据,运用Eviews软件对数据进行回归分析,得到沈阳市商品住宅价格变动回归方程,从而为房地产企业决策及政府制定政策提供理论依据。