创新投入对区域科技创新能力的影响研究——以江苏省为例

采用系统动力学方法,围绕政府、高校与企业3个主体构建系统动力学模型,探究不同因素对于江苏省科技创新能力的影响程度。结果显示：政府长期的科技支出与教育支出均能够促进江苏省科技创新水平的提升,但短期内加大教育支出并不能立竿见影;适当增加高校在校生人数有利于促进区域内发明专利的产出,提升江苏省科技创新水平;企业可适当加大对企业内部的R&D经费投入,促进企业创新性成果的产出,进而提升区域创新能力。     

Fiscal Stimulus in Times of High Debt: Reconsidering Multipliers and Twin Deficits

We investigate the impact of fiscal stimuli at different levels of the government debt‐to‐GDP ratio for a sample of 17 European countries from 1970 to 2010. This is implemented in an interacted panel VAR framework in which all coefficient parameters are allowed to change continuously with the debt‐to‐GDP ratio. We find that responses to government spending shocks exhibit strong nonlinear behavior. While the overall cumulative effect of a spending shock on real GDP is positive and significant at moderate debt‐to‐GDP ratios, this effect turns negative as the ratio increases. The total cumulative effect on the trade balance as a share of GDP is negative at first but switches sign at higher levels of debt. Consequently, depending on the degree of public indebtedness, our results accommodate long‐run fiscal multipliers that are greater and smaller than one or even negative as well as twin deficit and twin divergence behavior within one sample and time period. From a policy perspective, these results lend additional support to increased prudence at high public debt ratios because the effectiveness of fiscal stimuli to boost economic activity or resolve external imbalances may not be guaranteed.     

Investment Dynamics with Information Costs

Investment in physical capital at the microlevel is infrequent and large, or lumpy. The most common explanation for this is that firms face nonconvex physical adjustment costs. The model developed in this paper shows that information costs make investment lumpy at the microlevel, even in the absence of nonconvex adjustment costs. When collecting and processing information are costly, the firm optimally chooses to do it sporadically and to be inactive most of the time. This behavior results in infrequent and possibly large capital adjustments. The model fits plant‐level investment rate moments well, and it also matches some higher order moments of aggregate investment rates.     

系统动力学视角下城市群绿色低碳路径研究

碳达峰和碳中和的提出对城市群发展提出新的要求,城市群高速发展与环境问题间的矛盾日益加剧,绿色低碳发展路径亟待研究.以京津冀城市群为研究对象,在梳理城市群发展影响因素的基础上,分析城市群循环系统构成中要素间的关联关系,并通过量化模型,搭建基于系统动力学的城市群绿色低碳发展系统;重点从经济、能源、环境和城市聚合4个角度构建仿真系统,建立要素间量化函数,设定基本场景,以2010—2019年数据为基础,对系统进行仿真运行.算例结果表明,构建的仿真系统通过了检验,拟合程度较好;通过设计不同场景,验证相关参数变化时对系统运行的影响程度,发现综合场景对未来系统运行效益最佳,兼顾了经济发展与碳减排问题,能够促进城市向群绿色低碳发展.     

Smallholder land ownership in Kenya: distribution between households and through time

This study uses panel data to demonstrate two dimensions of land ownership: the distribution between households at a given time and changes within a household over time. We note that recognizing the latter dimension is only possible when analyzing rare long‐term panel data. We estimate a model for land ownership using a version of the correlated random effects estimator to uniquely identify the determinants of both dimensions amongst Kenyan smallholders. We find life cycle effects are a key determinant of both distributions, and identify important ways in which initial conditions such as inheritance and off‐farm income relate to the dynamics of ownership. We find that population density is a key determinant of differences between households, but also that a given household's land ownership is not affected in the short term as population density increases around them. Controlling for population density, households own more land when they are closer to road networks where the economic value of land is higher. We find important vulnerabilities for the land security of widows, but this vulnerability is geographically heterogeneous.     

基于系统动力学的农业订单融资研究——以奶牛养殖订单融资为例

近年来,随着供应链金融在全球的迅猛发展,中国农业订单融资应运而生,但对其研究尚待深入。从定量研究的角度,运用系统动力学方法,以奶牛养殖订单融资为例,建立奶牛养殖订单融资系统动力学模型,探讨农业订单融资运作的动态特性及其对供应链绩效的影响并通过模拟仿真分析农业订单融资相关参数的设定。最后,提出促进中国农业订单融资发展的具体建议。     

系统观视角下对中小企业融资问题的审视

中小企业融资是一个世界性难题。本文基于整体性、关联性、动态性等系统观,对中小企业融资难的原因进行了剖析,总结了中小企业融资难的四个内生性矛盾,认为解决中小企业融资难问题应该坚持系统性思维。以系统要素、系统环境之间的相互协调为目标,本文提出了解决中小企业融资难问题的总体思路、目标及对策建议。     

国外城市住房价格动态性研究综述

国外对住房价格动态性的研究分为四个方面:住房市场有效性的实证检验、宏观经济基本面指标的动态影响实证检验、住房价格泡沫的实证检验和住房价格指数的定价模型研究。本文对上述问题进行了文献综述,并进行相应的评价。     

Time-series–cross-section Data

This article treats the analysis of 'time-series–cross-section' (TSCS) data. Such data consists of repeated observations on a series of fixed units. Examples of such data are annual observations on the political economy of OECD nations in the post-war era. TSCS data is distinguished from 'panel' data, in that asymptotics are in the number of repeated observations, not the number of units.
The article begins by treating the complications of TSCS data in an 'old-fashioned' manner, that is, as a nuisance which causes estimation difficulties. It claims that TSCS data should be analyzed via ordinary least squares with 'panel correct standard errors' rather than generalized least squares methods. Dynamics should be modeled via a lagged dependent variable or, if appropriate, a single equation error correction model.
The article then treats more modern issues, in particular, the modeling of spatial effects and heterogeneity. It also claims that heterogeneity should be assessed with 'panel cross-validation' as well as more standard tests. The article concludes with a discussion of estimation in the presence of a binary dependent variable.     

National Health Service Boards of Directors and Governance Models

Abstract

This article reports the findings of a year-long research project focused on the activity of boards of directors of twenty-two trusts from the British National Health Service (NHS). The evidence gathered through the use of semi-structured interviews, focus groups, workshops, feedback questionnaires and document analysis indicates that the behavioural dynamics of boards, affected by the dominance of the expert model, act as antecedents of their statutory functions and the implementation of different governance models. Only a portion of the boards involved has effectively incorporated in its modus operandi post-New Public Management (post-NPM) principles of governance.