Evolving splines and seasonal unit roots in weekly agricultural prices

The univariate statistical properties of agricultural price series need to be examined as a first step in the analysis of price transmission mechanisms. However, in the case of weekly price series, increasingly available, the testing procedures usually applied in this step are not suitable to deal with evolving seasonal effects. In this study, a method of testing for seasonal unit roots in weekly series of agricultural prices is described. When the deterministic seasonal component does not remain constant over time, the restricted evolving spline model (RESM) is shown to be a useful parametric formulation to capture the deterministic seasonal pattern. Therefore, the RESM model should be included as a deterministic component in auxiliary regression for unit root tests at seasonal frequencies. This proposal is applied to three weekly series of Canary Islands banana prices. From the standard seasonal unit root tests, the null hypothesis is failed to be rejected at the 5% or 10% significance level at some seasonal frequencies for each one of the series. Once critical values are obtained by simulation exercises when the RESM model is included, the hypotheses of unit root are rejected at each one of the seasonal frequencies for all of the three series.     

关于兵团推进农业产业化经营有关问题的探讨

农业产业化经营是促进农业结构战略性调整的重要途经,是提高农业效益、增加农业市场竞争力、增加农民收入的有效举措。本文主要就兵团农业产业化经营现状及存在的主要问题及兵团推进农业产业化经营的优势等进行了分析,并提出进一步解放思想,更新观念,不断提高对推行农业产业化重要意义的认识;以市场为导向,加快垦区及农场经济的战略性调整,发挥垦区区域优势,培育主导产业和商品基地;加大对龙头企业和职工合作经济组织的扶持力度,在抓“龙头”企业组建产业集团上要有新的突破;要建立和完善产品产业化运行机制和监督约束机制;理顺利益关系,不断完善产业化经营的利益连接机制和加强领导,完善各种服务体系,积极扶持农业产业化健康发展等具体建议。     

基于回归分析法的南京市耕地面积变化影响因素分析

首先主要运用Excel预测南京市耕地面积减少的趋势;其次,通过文献阅读确定影响南京市耕地面积变化的影响因素,进而利用统计学方法建立了耕地面积与各个影响因素之间的回归分析模型;然后对模型所得结果的相关性进行统计性分析,剔除可能具有相关性的影响因素;最后把对各影响因素在南京市耕地面积变化的过程中按所起的正、负相关影响进行归类分析。旨在为南京市在抑制耕地面积锐减现象对相关因素的控制上提供相关的参考依据。     

2012年优秀青年科学基金女性获得者特征状况计量分析

以2012年优秀青年科学基金女性获得者为研究样本,通过对其当选年龄、工作地域、工作单位、留学状况、所在学部等要素进行计量研究,归纳、总结了该群体特征状况,并以此为基础对新时代中国女性科学家群体进行了深入剖析。     

Trade credit in SMEs: a quantile regression approach

This article analyses the determinants of the trade credit in Spanish manufacturing small and medium-sized enterprises (SMEs) from a new perspective. Specifically, we focus on the relationship between trade credit and other relevance financial resources: bank credit and self-financing. For the first time in the literature, a quantile regression approach is used, which takes into account the heterogeneity of firms in different quantiles of trade credit distribution. Our results show that the relationship between trade credit and other financial sources presents dissimilarities, including differences in sign, on SMEs with different degrees of trade credit. Our findings help to clarify the confusing results achieved in previous research on this topic.     

Lost in intervention. The Harrod–Balassa–Samuelson effect on the peseta/dollar real exchange rate (1870–1998)

We have decomposed the peseta/dollar real exchange rate (1870–1998) into its trend and cyclical components and used the former to proxy its time-varying equilibrium. Then, we have compared changes in the equilibrium with changes in the Spanish and the USA productivity differentials to identify years that do not fit with the Harrod–Balassa–Samuelson (HBS) hypothesis. The greatest maladjustment is found in the 1940s and 1950s, decades of strong exchange rate intervention in Spain. Conversely, the link between equilibrium and differentials adjusts to the hypothesis when using the non-intervened peseta/dollar exchange rate on the Tangier black market. These contrasting results back up the idea that exchange rate intervention, so common in developing countries, might explain their scanter evidence in favour of the HBS effect.     

虚拟组织持续创新能力作用机制研究

虚拟组织作为一种新兴的资源连接及能力重组的组织模式,彰显了其持续价值创新的优越性。虚拟组织持续创新能力是作用于持续创新系统中创新动力、创新过程、界面管理及组织学习的能力集合函数。首先,识别了虚拟组织持续创新能力的内涵与本质,剖析了虚拟组织持续创新能力形成机理;在此基础上,通过梳理创新能力维度划分相关文献,并结合虚拟组织的本质属性,对虚拟组织持续创新能力作用点进行解构;最后,构建了虚拟组织持续创新能力与持续创新系统之间以及各能力之间的交互作用机制,旨在深化对虚拟组织持续创新能力的研究和认识,丰富并拓展虚拟组织持续创新理论。     

略论经济增长由单纯依靠投资和净出口向二者与消费协调拉动的转变

在国内持续低消费的情况下,由于政府对投资和出口的过度激励,中国长期以来形成了主要依靠投资、净出口拉动的经济增长。主要依靠投资、净出口拉动的经济增长是不可持续的。实现经济增长主要依靠投资、净出口拉动向依靠消费、投资、净出口协调拉动转变的关键：一在于提高消费,二在于改变政府对投资和出口激励的方式与手段。     

OFDI逆向技术溢出、制度质量与区域创新能力

基于2005—2016年我国省际面板数据,首先通过OLS、DIFF GMM、SYS GMM3种基准线性回归方法论证了OFDI逆向技术溢出对我国区域创新能力的促进作用。以OFDI为核心解释变量,分别构建以地区腐败、市场化程度和知识产权保护为门槛变量的动态门槛回归模型。结果发现：随着地区腐败程度加深,我国区域创新能力逐渐减弱;以市场化程度、知识产权保护为门槛变量,跨越门槛点后OFDI对我国区域创新能力的拉动作用依次增强。最后,结合面板向量自回归模型进一步研究对外直接投资过程中地区腐败、市场化程度和知识产权保护对区域创新能力的动态即期冲击。结果显示:市场化程度单位变动对区域创新能力的影响呈现正向冲击且持续性较强,知识产权保护对区域创新能力的拉动最为迅速但后期持续性较弱,地区腐败对区域创新能力产生负向冲击作用。     

Adam Smith on lotteries: an interpretation and formal restatement

The paper concerns a neglected aspect of the Wealth of Nations (with the notable exception of D. Levy 1999 Levy, D. M. 1999. “Adam Smith’s Katallactic Model of Gambling: Approbation from the Spectator.” Journal of the History of Economic Thought 21 (1): 81–91. doi:10.1017/S1053837200002868.[Crossref] , [Google Scholar]), dealing directly with decision under risk. In a few pages from book I, chapter 10, Adam Smith explicitly named “lotteries” various objects of choice (possible occupations, or investment opportunities, for instance) and provided an analysis which standard expected utility glasses would hardly fit. Taking this into account allows a better understanding of the part played by typical characters like the “projector” or the “sober man”, in such matters as Smith’s conception of entrepreneurship or of the credit market. The use of some modern concepts in decision analysis (inverse stochastic dominance, rank dependent utility, prudence toward risk), is a means to show the existence, in Smith’s work, of an original theory from decision under risk, where his analysis of lotteries in the Wealth of Nations is consistent with statements from his moral philosophy on asymmetric sensitivity to gains and losses and to the regulating part played by the impartial spectator.