关键词： 时滞   经济模型   Hopf分岔  

摘要： 利用特征值方法,讨论了一类具有时滞的宏观经济模型局部渐近稳定和局部Hopf分岔的存在性,得到模型产生局部Hopf分岔的时滞临界点.研究表明,有效控制或者延迟Hopf分岔的产生,有利于市场的健康发展.最后利用仿真示例,验证了所得结果的正确性.

关键词： Measurement error   Subjective expectations   Stock market participation  

摘要： Subjective expectations are important primitives in many economic models, yet their direct measurement often yields imprecise and inconsistent data. This has previously been treated as a pure measurement error problem. In contrast, this paper argues that the individual-level precision of such data may reflect the structure of the underlying decision process. We estimate a semiparametric double index model on data specifically collected for this purpose and show that stock market participation decisions exhibit little variation in economic model primitives when individuals provide error-ridden belief statements. In contrast, beliefs and risk preferences predict strong variation in stock market participation for individuals who report precise expectations measures. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Cattle   Farm model   Intensification   Agro-ecology   Climate change  

摘要： How do we plan future sustainable livestock farming systems? Some argue that intensive, specialized systems are more efficient and emit fewer pollutants;others claim that integrated, diversified farming systems are more beneficial to both society and the environment. Bio-economic farm models can help decision-makers and researchers analyze the trade-offs among the numerous possibilities, and direct future livestock production toward greater sustainability. The Orfee model described and evaluated here was developed with this aim. It covers a broad range of beef and dairy systems and forage and crop production alternatives that may be managed with varying levels of intensity (breed, production objective, crop operations, etc.) and integration (crop rotation, organic fertilization, calving period, animal diets, etc.). Capital is also included in the optimization process, with trade-offs between production, labor, machinery and buildings. Environmental impact is assessed through potential impact on climate change.

关键词： Air pollution   Socioeconomic burden   China   Computable general equilibrium  

摘要： In this study, we apply to China the China Regional Energy Model, developed as part of the Regional Emissions Air-Quality Climate Health (REACH) assessment framework, and estimate PM2.5-associated health costs. We estimate that, in 2015, exposure to PM2.5 caused a nationwide welfare loss of US$248 billion (3.6% of the baseline welfare level). Over half the cost is from mortalities associated with chronic exposure, followed by broader economic loss (38%) and direct loss from short-term exposure (9%). The cost varies among provinces (0.5%-5.8% of the baseline welfare level), due to subnational heterogeneity in air quality, population density, and income levels. The cost in absolute terms is large in populous, coastal provinces, such as Shandong, Jiangsu, Zhejiang, and Guangdong, but when the local economy size is controlled for, the Greater Beijing area and central inland provinces also suffer large welfare losses in relative terms. (C) 2017 Elsevier B.V. All rights reserved.

关键词： ELECTRIC utilities   CUSTOMER services   ECONOMIC models   DECISION making   SCALABILITY (Systems engineering)   SOUTH Africa  

摘要： Cost of unserved energy provides an economic measure of the cost of electricity interruptions to electricity customers. These values inform investment and refurbishment decisions related to the power system, with the aim of optimizing network reliability. This paper reports on the development of an economic model to estimate the value of electricity reliability in South Africa by Eskom to meet regulatory requirements. The model allows for the scalability of COUE from national level to more detailed resolutions. The impact is that decisions for power system investment can be made to meet the needs of planning and regulatory applications. (C) 2017 Published by Elsevier Ltd.