Aggregation in Input–Output Models: Prices and Quantities

This paper develops a joint theory of aggregation of input–output quantity and price models. The main emphasis is on the problem of aggregation of industries in the models. While aggregation of quantity models is a familiar topic in economic literature, the aggregation of price models is a largely unexplored subject. Here, however, quantity and price models are considered as two parts of a single, composite flow model. This understanding implies that each result in the quantity model has dual counterpart in the price model and vice versa. Through consistent use of this duality principle, significant results are developed for both model types, and a number of well-known results can be stated in a simpler way. Specifically, a number of conditions for perfect aggregation of final demands, primary inputs and industries in price models as well as quantity models are formulated. On this basis a new indicator of aggregation bias is suggested. The indicator can be decomposed into the contributions of each detailed industry, enabling the user to identify atypical industries in each group. Furthermore, the indicator can be computed even with no knowledge of the coefficients of the detailed models.     

Dynamics of Wheat Prices in the Wake of Market Reforms: The Case of Pakistan

Using Autoregressive Conditional Heteroskedastic (ARCH) method, this paper examines the effects of market reforms on the distribution of real mean prices and their variability before and after reforms. It is found that market-oriented reforms benefited producers and consumers alike. Empirical evidences, generally, support theoretical assertion that mean prices decline in most urban areas and increase in those markets that are located in surplus producing areas. The results also showed that market reforms lead to more price volatility.     

房价影响因素的实证分析——以青岛市为例

运用SPSS软件,以人口、人均GDP、住房销售面积和房地产开发投资为自变量,采用2000～2009年10年的数据,建立了多元线性回归模型,对青岛市房价这一因变量进行了模拟分析。模型通过各种检验,得出了影响青岛市住房价格最重要的因素是市区人口这一结论,说明青岛市有效的需求增大,是抬高住房价格十分重要的因素,这在一定层面上说明了青岛的住宅市场的价格是比较正常的价格。     

地铁工程土建施工招标中工程量清单及控制价的编制

随着地铁工程建设项目的增多,如何在招投标阶段做好工程造价的控制显得日益重要,本文从工程量清单和控制价的编制两个方面进行了阐述。     

公司治理对企业资本结构动态调整速率的影响

本文基于2000—2013年中国上市公司数据,通过构建反映公司治理水平的G指标,来研究公司治理水平对企业资本结构调整速率的影响,并引入产品市场竞争程度指标——布恩指数考察这一外部因素的作用效果,进而比较分析公司治理环境对企业调整资本结构速率的差异化影响。研究结果显示,公司治理水平低的企业,其资本结构调整速率相应较低;产品市场竞争愈激烈,企业资本结构调整速率愈快,这种情况在公司治理水平低的企业中体现得更为明显;对于不同负债类型的企业,公司治理水平低的企业资本结构调整速率均低于公司治理水平高的企业,但是原因却不尽相同。这一研究对现实中企业改善公司治理水平,利用债务这一有效工具缓解股东与经理人之间的矛盾,制定融资决策、优化企业资本结构以及提高企业绩效具有重要的指导意义。     

投资者信念异质性和适应性对股市价格的影响

考察了异质性信念、具有适应性的交易者相互作用下股市价格行为。通过数字模拟,分析实际市场上常用的价值分析和技术分析策略对价格动力学的作用,说明不同参数对价格行为的影响。     

Trade,competitiveness and investment: an empirical assessment

ABSTRACT

The Eurozone crisis has exposed several weaknesses of the European Monetary Union economies. This paper aims to assess the impact on external competitiveness of an expansionary capital stock policy that could contribute to reduce the trade balance asymmetries within the EU and help European exporters to recover their competitive role in international markets. A policy action to increase capital stock accumulation through investment in selected European countries could generate a double dividend: increasing both price and nonprice competitiveness, so stimulating their competitive position as exporters, and consolidating the growth path of EU economy. The analysis employs a bilateral trade model built at INFORUM with several distinguishing characteristics: a comprehensive bilateral data set, econometric estimation of key parameters, and emphasis on sectoral details. Our findings show that a capital stock increase is effective in narrowing trade imbalances within EU. Heterogeneous effects are estimated for commodities in China and the US.     

共享经济下产业价值网络创新的系统动力学分析

共享经济给产业价值网络的发展带来了新的挑战与机遇,只有不断加大产业价值网络的创新力度,才能充分把握共享经济带来的发展机遇,实现产业的现代化发展.文章以J省农业共享经济领域的茶叶产业价值网络为案例,采用系统动力学方法建立共享经济下产业价值网络创新的系统动力学模型,并以A茶产业集团共享经济平台的相关运营数据为例进行定性与定...     

The Dynamics of Self-Esteem and Physical Self: Between Preservation and Adaptation

The aim of this study was to model and characterize the psychologicalprocesses that underlie the dynamics of global self-esteem and physicalself over time. Twice a day for 228 consecutive days, seven participantscompleted a short inventory (PSI-6, Ninot et al., 2001) measuring sixsubjective dimensions: global self-esteem, physical self-worth, physicalcondition, sport competence, physical strength, and attractive body.Each series was modeled by means of ARIMA procedures. The resultsshowed that a simple moving average model provided a satisfactoryaccount for the dynamics of all series. This model suggests that acombination of two opposite processes underlies the dynamics ofself-concept: preservation, which tends to restore the previousvalue after a disturbance, and adaptation, which tends to inflectthe series in the direction of the perturbation.     

Spatial Spillovers Revisited: Innovation,Human Capital and Local Dynamics

This symposium focuses on understanding key territorial‐level innovation trends and processes by country, region and technology. It questions various widely accepted assumptions, offers fresh perspectives, both conceptually and methodologically, and challenges a paradigm shift in the field of innovation and spatial dynamics. It consists of three articles analysing at different scales (urban, regional and national) the territorial dynamics of innovation and their determinants. The innovation process, with local symbiosis and spatial spillovers at its core, is analysed within the conceptual framework of national and regional innovation systems and regional economic development. Based on a discussion of spatial spillovers and the way they shape the evolutionary and symbiotic relationships between local agents and actors, including university, industry and local development agencies, the symposium highlights the relevance of this framework for a better understanding of the transformation of local economic development processes. It investigates the differences in the geography of innovation regarding different institutional settings, different systems of innovation, and different national innovation strategies. While addressing mainly the EU, the US, and emerging countries such as China and India, the contributions also highlight the critical role of current innovation policies from a general perspective. In so doing, the symposium recognizes a contrarian perspective that argues that contemporary information and communication technologies (ICTs) provide a way to leapfrog the dominant role of proximity in innovation processes, creating a complimentary rather than a substitution effect for more remote and peripheral places. That said, this symposium focuses primarily on an urban network view of the innovation process and proximal effects in this context.     

中国畜产品价格的实证分析——基于季节调整模型与两阶段协方差方法

本文以2001年1月—2014年5月的畜产品价格为研究对象,利用 X-12-ARIMA 季节调整模型分析影响畜产品价格波动的相关因素,并利用协方差计算季节性影响、长期周期性影响、不规则影响对畜产品价格波动的贡献程度,进一步利用两阶段协方差纵向对比分析各影响因素贡献度的变化,最后发现长期驱动因素和季节性因素是中国畜产品价格波动的主要因素;从纵向对比来说,鸡蛋、鸡肉、猪肉价格的不规则影响因素的影响作用在减弱,鸡肉、猪肉价格的季节性影响因素的作用在减弱。     

港口竞争力的系统动力学分析

现今港口之间的竞争日趋激烈,提升港口的国际竞争力才能使其生存和发展。为此,文中在对影响港口的主要因素进行分析的基础上,运用系统动力学的方法分析了主要因素之间的因果关系,并建立了系统仿真流图,为港口的发展决策提供了理论依据和可以借鉴的方法。     

系统动力学在项目管理中的应用

针对传统项目管理方法在宏观控制方面存在的不足,分析项目管理的特点,依据系统动力学原理,结合项目动态系统的特征,建立了一个系统动力学模型.它更侧重于项目的宏观管理,侧重于对难以准确量化的复杂因素的分析,使项目管理更加科学化.     

Retracted: Dynamics of Unclosed Triangles in Alliance Networks: Disappearance of Brokerage Positions and Performance Consequences

We depart from previous research on brokerage advantages in interorganizational networks by shifting focus to the dynamics of brokerage positions. We investigate causes of the disappearance of these positions and its influence on organizational performance. Using a subnetwork consisting of a broker and its two partners as the unit of analysis, we postulate that the brokerage position disappears either when the two partners develop ties or when the ties between the broker and the partners dissolve. We predict that the patterns of interactions in which this subnetwork is embedded exert multilevel influences on the disappearance, and that embedded structures promoting persistence constrain brokerage advantages. Our analysis of codeshare alliance data in the global airline industry supports the theory and demonstrates that the persistence of brokerage positions decreases broker performance. The findings explain why brokerage positions rarely persist and why the persistence of brokerage positions does not benefit brokers.     

基于广联达软件计算工程量与手工计算工程量对比浅析

软件算量是目前工程造价计算中工程量计算的一种简便方法,通过对广联软件算量和手工计算工程量的结果进行分析,找出两者的优缺点,为实际工程应用中,针对具体工程选用合适的计算方法,给造价人员提出参考。     

Determinants and Dynamics of Current Account Reversals: An Empirical Analysis

We use panel probit models with unobserved heterogeneity, state dependence and serially correlated errors in order to analyse the determinants and the dynamics of current account reversals for a panel of developing and emerging countries. The likelihood‐based inference of these models requires high‐dimensional integration for which we use efficient importance sampling. Our results suggest that current account balance, terms of trades, foreign reserves and concessional debt are important determinants of current account reversal. Furthermore, we find strong evidence for serial dependence in the occurrence of reversals. While the likelihood criterion suggest that state dependence and serially correlated errors are essentially observationally equivalent, measures of predictive performance provide support for the hypothesis that the serial dependence is mainly due to serially correlated country‐specific shocks related to local political or macroeconomic events.     

NGW型行星减速器虚拟样机及动力学仿真分析

本文以NGW型减速器为例,运用pro/e4.0对行星齿轮减速器进行三维实体建模,并将建立好的模型经过干涉检验,虚拟装配,再通过Pro/e与adams之间的接口导入到adams中进行动力学仿真分析,经过分析,验证此行星减速器在动力学设计方面的合理性。     

理论物理研究领域的结构和动态

本篇文章从近年来Physical Review D的相关数据文献出发,浅要论述了理论物理研究领域的结构与动态,仅供参考。