The impact of environmental regulations on forest product trade in China

Forest product trade plays an important role in the development of the Chinese forest industry. The trading value of forest product has shown a yearly growth rate of 12% during the last five recent years. Stringent environmental regulations in China have a profound impact on raw material supplies and industrial production in the forest sector; however, their impact on the forest product trade is still unclear. This study applies fixed and random effects models as well as a seemingly unrelated regression model to investigate the impact of environmental regulations on the trade of forest product from 2002 to 2015. The results indicate that the stringent environmental regulations promoted the import but restricted the export of forest product in general. Specifically, the stringent environmental regulations stimulated the import but had an ambiguous impact on the export of the paper product. The stringent environmental regulations had also stimulated the import of wood product but inhibited the export. In contrast, wooden furniture had been affected minimally; only export got slightly negatively affected by environmental regulations. Recommendations for resource managers:

• Trade‐offs between economic growth and environmental regulations are needed to smoothly promote the forest product trade in China.
• Paper and wooden furniture product sectors are less likely to be affected by stringent environmental regulations, because high value‐added products could compensate for environmental costs.
• The wood product sector is more likely to be negatively affected by stringent environmental regulations because environmental costs could severely impact the competitiveness of low value‐added products.

     

Environmental impact assessment and ranking the environmental projects in Jordan

The Nominal Group Technique as a structured group decision process and PROMETHEE as a Multi-Criteria Decision Aid software are utilised to develop a reliable methodology to prioritise environmental projects in Jordan and to evaluate their environmental impacts. This methodology is novel in that it integrates the various analytical decision management techniques in order to increase the flexibility and efficiency of the environmental planning. This methodology is then implemented on a sample of wastewater projects in Jordan, and the results are discussed.     

Assessing the impact of the environmental contamination on the transmission of Ebola virus disease (EVD)

This paper deals with the following biological question: how influential is the environmental contamination on the transmission of EVD? Based on the works in (Bibby et al., Environ Sci Technol Lett 2:2–6, 2015; Leroy et al., Nature 438: 575–576, 2005; World Health Organization. Unprecedented number of medical staff infected with Ebola), we design a new mathematical model to address this question by assessing the effect of the Ebola virus contaminated environment on the dynamical transmission of EVD. The formulated model captures two infection pathways through both direct human-to-human transmission and indirect human-to-environment-to-human transmission by incorporating the environment as a transition and/or reservoir of Ebola viruses. We compute the basic reproduction number \({\mathcal {R}}^{env}_0\) for the model with environmental contamination and prove that the disease-free equilibrium is globally asymptotically stable (GAS) whenever \({\mathcal {R}}^{env}_0 \le 1\). When \({\mathcal {R}}^{env}_0 > 1\), we show that the said model has a unique endemic equilibrium which is GAS. Similar results hold for the free environmental contamination sub-model (without the incorporation of the indirect transmission). More precisely, for the latter model, calculate the corresponding basic reproduction number \({\mathcal {R}}^{h}_0\) and establish the GAS of the disease-free and endemic equilibria, whenever \({\mathcal {R}}^{h}_0 \le 1\) and \({\mathcal {R}}^{h}_0 > 1\), respectively. At the endemic level, we show that the number of infected individuals for the full model with the environmental contamination is greater than the corresponding number for the free environmental contamination sub-model. In conjunction with the inequality \({\mathcal {R}}^{h}_0 < {\mathcal {R}}^{env}_0\), our finding suggests a negative answer to the biological question under investigation, i.e. the contaminated environment plays a detrimental role on the transmission dynamics of EVD by increasing the endemic level and/or the severity of the outbreak. Therefore, it is natural to implement a control strategy which aim at reducing the severity of the disease by providing adequate hygienic living conditions, educate populations at risk to follow rigorously those basic hygienic conditions as well as ask them avoid contact with suspected contaminated objects. Further, we perform numerical simulations to support the theory.     

How to measure the impact of environmental factors in a nonparametric production model

The measurement of technical efficiency allows managers and policy makers to enhance existing differentials and potential improvements across a sample of analyzed units. The next step involves relating the obtained efficiency estimates to some external or environmental factors which may influence the production process, affect the performances and explain the efficiency differentials. Recently introduced conditional efficiency measures (,  and ), including conditional FDH, conditional DEA, conditional order-m and conditional order-α, have rapidly developed into a useful tool to explore the impact of exogenous factors on the performance of Decision Making Units in a nonparametric framework. This paper contributes in a twofold fashion. It first extends previous studies by showing that a careful analysis of both full and partial conditional measures allows the disentangling of the impact of environmental factors on the production process in its two components: impact on the attainable set and/or impact on the distribution of the efficiency scores. The authors investigate these interrelationships, both from an individual and a global perspective. Second, this paper examines the impact of environmental factors on the production process in a new two-stage type approach but using conditional measures to avoid the flaws of the traditional two-stage analysis. This novel approach also provides a measure of inefficiency whitened from the main effect of the environmental factors allowing a ranking of units according to their managerial efficiency, even when facing heterogeneous environmental conditions. The paper includes an illustration on simulated samples and a real data set from the banking industry.     

Security investment and information sharing in the market of complementary firms: impact of complementarity degree and industry size

We study a differential game of information security investment and information sharing in a market consisting of n complementary firms. Two game approaches, the non-cooperative game and the totally cooperative game, are employed to investigate the steady state strategy of each firm. Under certain conditions, a unique steady state can be obtained for both games. We find that the steady state security investment and information sharing level are not always less in the non-cooperative game than that in the totally cooperative game. In addition, some theoretical analyses are made on the impacts of the complementarity degree and industry size on firms’ steady state strategies for both games. Finally, some numerical experiments are conducted to give some insights related to the instantaneous profit in the steady state. It can be found that a firm will obtain more instantaneous profit in the steady state of the totally cooperative game than that of the non-cooperative game, which emphasizes the importance of coordinating strategies. The effects of the complementarity degree and industry size on the instantaneous profits in the steady state are also obtained through the numerical experiment results.     

Modeling the governance of cooperative firms

Most studies of cooperative firms have been conducted using neoclassically inspired economic models that consider the characteristics and behavior of capitalist companies and their owners, thus failing to accommodate the wide range of criteria that motivate the creation of cooperative firms. These models have traditionally been at odds with the real objectives of cooperative firms due to their inability to accommodate a series of often conflicting criteria. We put forth a set-theoretic model of governance of cooperative firms that allows us to investigate how different models of cooperative governance can be implemented and how cooperative decision-making can be solved using a multicriteria decision analysis approach.     

Scale directional distance function and its application to the measurement of eco-efficiency in the manufacturing sector

Directional distance function (DDF) is a recognized technique for measuring efficiency while incorporating undesirable outputs. This approach allows for desirable outputs to be expanded while undesirable outputs are contracted simultaneously. A drawback of the DDF approach is that the direction vector to the production boundary is fixed arbitrarily, which may not provide the best efficiency measure. Therefore, this study extends the previous framework of efficiency analysis to introduce a new slacks-based measure of efficiency called the scale directional distance function (SDDF) approach. This new approach determines the optimal direction to the frontier for each unit of analysis and provides dissimilar expansion and contraction factors to achieve a more reasonable eco-efficiency score. This new approach is employed to measure the eco-efficiency of the Malaysian manufacturing sector. In addition, the paper demonstrates the use of the new approach to establish target values for the reduction/expansion of outputs in order for the inefficient DMUs to achieve full eco-efficiency. The results indicate that Melaka, Pulau Pinang, Negeri Sembilan, Sabah, Sarawak and Labuan have attained full eco-efficiency while Terengganu is the least eco-efficient. The overall eco-efficiency of the manufacturing sector in Malaysia is 80.5 % with wide variations across the states.     

The impact of environmental constraints on short term harvesting: Use of planning tools and mathematical models

Both in New Zealand and Chile there exist important forest industries based mostly on pine plantations. The management of harvesting requires a series of activities such as building access roads, harvesting with skidders on flat terrain and cable logging for steep terrain, transportation from forest origins to destinations, such as a port, pulp plant and sawmills.These harvesting activities imply some potentially harmful environmental impacts such as water sedimentation, erosion and loss of scenic beauty. This has led to the proposal of several mitigating actions, such as creating riparian strips along rivers, avoiding the use of heavy machinery on fragile soils and minimizing road building.The degree of implementation of these mitigating actions differs in Chile and New Zealand. In New Zealand, the 1991 Resource Management Act regulated the implementation of environmental protection measures. In Chile a series of such measures have been implemented, but a set of definite regulations has not been defined yet and there is a need to develop an economic evaluation of the implementation of environmental measures in terms of reduced timber production and high harvesting costs, together with the benefits to the environment. To support decisions at tactical and operational levels, mathematical models have been developed both in Chile and New Zealand and are being used successfully by the timber industries. These models can be modified to consider diverse environmental protection measures. We analyze the implementation of these modifications and how the new models can help evaluate the economic impact of the protection measures. We show some preliminary results.     

Integrating expert weighting and multi-criteria decision making into eco-efficiency analysis: the case of US manufacturing

In this paper, the effect of weighting strategies on sustainability performance assessment is addressed. Eco-efficiency is used as the main metric for sustainability performance evaluation. An integrated input-output life cycle assessment (LCA) and multi criteria decision making (MCDM) approach is employed. The US manufacturing sectors’ LCA results are used in conjunction with the proposed MCDM framework to perform the eco-efficiency evaluation of 276 US manufacturing sectors. Five environmental impact categories are considered as the negative factors, namely: greenhouse gas emissions, energy use, water withdrawal, hazardous waste generation and toxic releases into air and the economic output of each manufacturing sector is considered to be the positive output. To study the overall impact of different weighting strategies; twenty weighting scenarios are designed. Five pairs of weights considered for the overall economic versus environmental impacts along with four specific weighting strategies based on Harvard, SAB, EPP and Equal weighting for each pair. According to the results of the statistical analysis, it is concluded that the weighing strategies applied to the overall environmental impacts and economic outputs cause statistically significant differences in the eco-efficiency scores.     

Dynamics of the cournot oligopoly with multi-product firms

The stability of the Cournot equilibrium for a linear oligopoly with multiproduct firms is analyzed. Under certain conditions, the equilibrium is proven to be stable independently of the values of the adjustment coefficients in the case of a continuous time system. However, it is stable only in duopoly for a discrete system of adjustment.     

Capacity competition of make-to-order firms

Two make-to-order firms, each modelled as a single-server queue, compete for a common stream of (potential) customers by setting their service capacities (rates) and service prices. Each customer maximizes her expected return by getting service from a firm or by balking. We completely characterize the Nash equilibrium of the competition.     

Comments on the impact effect

The relations of stereomechanical impact are proved by taking the limit as the impact time tends to zero. A generalized Kelvin formula for the change in kinetic energy during impact is given as an example.     

我国AB股双重上市公司经营业绩变化的实证分析

本文以46家在上海和深圳同时上市AB股的公司的样本,分析了公司实行双重上市前1年及其后4年的经营业绩的变化趋势以及股权结构和上市顺序对它的影响。研究表明,双重上市当年及其后4年经营业绩显著下降;股权结构和上市顺序对公司经营业绩影响明显。最后,文章提出了改善AB股公司经营业绩的对策建议。     

管理者过度自信对高技术企业技术外部获取方式选择的影响研究

企业管理者的业绩预测偏差是衡量管理者是否过度自信的一个重要体现,值得关注和研究。本研究采用我国2004~2013年高技术上市公司的相关数据,应用Ordered-probit模型实证分析了管理者过度自信对高技术上市公司技术外部获取方式选择的影响。研究结果表明:我国高技术上市公司以非股权技术联盟作为首要的技术外部获取方式,公司风险投资是最后的选择;同时,研究发现:在对技术外部获取方式进行选择时,管理者过度自信的高技术上市公司选择并购优先于合资和少数持股联盟,而管理者非过度自信的高技术上市公司选择少数持股联盟优先于并购和合资。该研究方法简单、高效、合理,是企业高管提升公司管理水平和科学获取技术外部的一种新的方法选择。     

A note on price and quality competition between asymmetric firms

This paper analyzes the impact of asymmetry between firms on the outcome of price and quality competition from a microeconomic viewpoint. Consumers purchase a product based on not only its price but also its quality level; therefore, two firms compete in determining their prices and quality levels to maximize their profits. The asymmetry arises from the difference in consumers’ loyalty to each firm; that asymmetry then determines a character of differentiation between firms. Our purpose is to show how asymmetry influences competition under varying consumers’ price- and quality-sensitivity. In doing so, we extend earlier work in the area of price and quality competition. We show that in both the moderately quality-sensitive and price-sensitive markets, higher consumers’ sensitivity as well as lower consumers’ loyalty to any firm leads to intense competition, resulting in a decrease of both firms’ equilibrium profits. On the other hand, in highly quality-sensitive market, asymmetry compels the smaller firm to change its competitive strategy. In general, this is more beneficial to the larger firm, as the smaller firm’s profit tends to decline. In the worst case, the smaller firm is driven out of business under equilibrium.     

基因调控网络的边预测

为构建基因调控网络,提出了一个基于基因表达水平和网络反传递的算法.该算法用网络反传递思想来分析由传统相关性计算方法产生的间接效果,并考虑了调控网络的稀疏性,在模型算法中加入了控制网络稀疏性的l_1范数惩罚项.在大肠杆菌实验数据上测试该算法,这种方法提高了相关性分析对调控网络中边的预测能力,皮尔逊相关系数提高了6.42%,斯皮尔曼相关系数提高了5.92%,互信息提高了9.35%.总的来说,这个模型为修饰大量系统的相关性数据提供一种新思路,可以应用到网络边的预测和推断生物网络的控制动力学中.     

Mathematics standards and curricula in the Netherlands

This paper addresses the question of what mathematics Dutch students should learn according to the standards as established by the Dutch Ministry of Education. The focus is on primary school and the foundation phase of secondary school. This means that the paper covers the range from kindergarten to grade 8 (4~14 years olds). Apart from giving an overview of the standards, we also discuss the standards' nature and history Furthermore, we look at textbooks and examination programs that in the Netherlands both have a key role in determining the intended mathematics curriculum. In addition to addressing the mathematical content, we also pay attention to the way mathematics is taught. The domain-specific education theory that forms the basis for the Dutch approach to teaching mathematics is called “Realistic Mathematics Education” Achievement scores of Dutch students from national and international tests complete this paper. These scores reveal what the standards bring us in terms of students' mathematical understanding. In addition to informing an international audience about the Dutch standards and curricula, we include some critical reflections on them.     

Field-based hypotheses on advancing standards for mathematical practice

The Common Core State Standards in Mathematics (CCSSM, 2010) are organized around two types of standards: the standards for mathematical content and standards for mathematical practice. The central goal of this paper is to present cognitive and instructional analyses of standards for mathematical practice through a discussion of field-based activities with inservice secondary mathematics teachers and students. A potential value of the study is that it provides researchers with specific field-based hypotheses on advancing standards for mathematical practice.