A New Test for Short Memory in Long Memory Time Series

This article considers short memory characteristics in a long memory process. We derive new asymptotic results for the sample autocorrelation difference ratios. We used these results to develop a new portmanteau test that determines if short memory parameters are statistically significant. In simulations, the new test can detect short memory components more often than the Ljung-Box test when these short memory components are in fact within a long memory process. Interestingly, our test finds short memory autocorrelations in U.S. inflation rate data, whereas the Ljung-Box test fails to find these autocorrelations. Modeling these short memory autocorrelations of the inflation rate data leads to improved model accuracy and more precise prediction.     

Exact calculation of power and sample size in bioequivalence studies using two one‐sided tests

The number of subjects in a pharmacokinetic two‐period two‐treatment crossover bioequivalence study is typically small, most often less than 60. The most common approach to testing for bioequivalence is the two one‐sided tests procedure. No explicit mathematical formula for the power function in the context of the two one‐sided tests procedure exists in the statistical literature, although the exact power based on Owen's special case of bivariate noncentral t‐distribution has been tabulated and graphed. Several approximations have previously been published for the probability of rejection in the two one‐sided tests procedure for crossover bioequivalence studies. These approximations and associated sample size formulas are reviewed in this article and compared for various parameter combinations with exact power formulas derived here, which are computed analytically as univariate integrals and which have been validated by Monte Carlo simulations. The exact formulas for power and sample size are shown to improve markedly in realistic parameter settings over the previous approximations. Copyright © 2014 John Wiley & Sons, Ltd.     

关键审计事项披露对企业创新投入的影响

以2016—2019年2826家A股上市公司为样本,研究了关键审计事项披露对企业创新投入的影响。结果发现,关键审计事项披露对企业创新投入具有显著的正向影响。进一步研究发现,董事会效率在关键审计事项披露与企业创新投入之间具有部分中介作用;监事会规模对关键审计事项与企业创新投入二者关系具有负向调节作用;在不同供应链集中度的企业中,关键审计事项披露对企业创新投入的影响具有异质性。据此,建议企业管理层积极分析关键审计事项,帮助利益相关者全面准确了解关键审计事项的相关内容;企业董事会及监事会充分把握与注册会计师沟通的机会,提高企业创新投入的决策能力及监督能力。     

合理商品流通规模形成机制研究

合理商品流通规模的质的含义 ,是指商品流通规模的大小能够使商品流通系统经营服务能力达到最大化 ,并能够使国民经济系统处于良性循环的运动状态。合理商品流通规模量的含义 ,是指商品流通规模的大小必须适合社会再生产过程中各种因素所能承受的数量界限的可能性。商品流通规模合理化的指标体系由总量标准、结构标准和效率标准三大部分组成。商品流通规模扩张的动力结构 ,由原生动力、直接动力和间接动力组成。商品流通规模的调节机制 ,则由自我调节机制和宏观调节机制组成。     

On a Pandemic Threshold Theorem of the Early Kermack–McKendrick Model with Individual Heterogeneity

A pandemic threshold theorem of the Kermack–McKendrick epidemic system with individual heterogeneity is proved from the definition of R ₀ by Diekmann, Heesterbeek, and Metz. The early Kermack–McKendrick epidemic model is extended to recognize individual heterogeneity, where the state variable indicates an epidemiological state or genetic, physiological, or behavioral characteristics such as risk of infection. With the basic reproduction number R ₀ for the heterogeneous population, the final size equation of the limit epidemic starting from a completely susceptible steady state at t = ?∞ has a unique positive solution if and only if R ₀  > 1. The main result is that the positive solution of the final size equation gives the lower bound of the intensity of any epidemic starting from a host population composed of susceptible and a few infected individuals who spread on a noncompact domain of the trait variable.     

农村劳动力流出与粮食规模化生产：“一致”抑或“冲突”？——基于湖南乡村调查分析

农村劳动力流出对粮食规模化生产有重要影响。本文通过对湖南不同类型村庄的实地调查,发现农村劳动力流出对粮食规模化生产影响是有差异的．那些粮食生产条件相对较好村庄的劳动力不断流出有利于加快推进粮食适度规模化生产．但要想使规模化水平达到理想状态还需要政府实施组合拳。而在那些粮食生产条件相对较差村庄的劳动力不断流出并不一定能促进粮食规模化生产．相反还可能抑制其发展。为推进农村劳动力有序流出和加快粮食适度规模化生产．在保障农村流出的劳动力就业基础上．应该加快培养留守职业农民和制定支持粮食规模化生产的激励政策．降低农户种粮的成本．增强规模化种粮的吸引力。     

金融规模、所有制结构与城镇就业容量——基于1997—2012年中国省级面板数据的分析

基于1997—2012年中国省级面板数据,运用系统广义矩估计法(SYSGMM),估计了金融规模对于城镇就业容量的效应,并对不同样本组分别估计,以观察地区差异。整体估计结果表明,无论以人员规模还是以增加值规模作为解释变量,估计系数均显著为正,其平方项的系数显著为负。这意味着金融规模能够促进城镇就业,但该效应递减,超过一定临界值将转为抑制效应。分组估计结果表明,金融规模扩张的就业效应在非公有制经济较发达的地区更明显,在非公有制经济欠发达的地区不明显,甚至表现为抑制效应。这意味着一个地区的所有制结构对金融规模与城镇就业的关系有重要影响。为增进金融发展的就业效应,我国一方面应讲求金融增长质量,实现有序适度扩张;另一方面要深化企业改革,激励非公有制经济进一步释放市场活力,以消除金融系统在资源配置中的扭曲效应。     

政府规模、支出结构与经济增长：基于中国数据的经验研究

借以一个标准的新古典经济增长模型为基础,利用中国各省区的数据,考察政府规模和政府支出结构对经济增长的影响,希望为理解中国经济持续增长提供一个视角。研究结果表明,在本区间里,地方政府规模与地区劳动生产率水平之间显著正相关,但与地区劳动生产率增长关系不明显;在一定程度上,地方政府效率与政府规模之间存在替代关系;地方政府的生产性支出和非生产性支出对生产率增长均有积极影响;地方财政支出结构对投资有十分显著的影响,反映了地方政府有很强的投资偏好。     

Government size and economic growth in Taiwan: A threshold regression approach

The Armey curve developed by [Armey, R. (1995). The freedom revolution. Washington, DC: Rognery Publishing Co.] and [Vedder, R. K., & Gallaway, L. E. (1998). Government size and economic growth. Joint Economic Committee] demonstrates that there is a non-linear relationship between government size and economic growth. In order to search for the threshold effects, this paper employs [Hansen, B. E. (2000). Sample splitting and threshold estimation. Econometrica, 68(3), 575–603] threshold regression model to test whether the Armey curve exists in Taiwan, allowing for endogenous government size thresholds. We apply the two-sector production function developed by [Ram, R. (1986). Government size and economic growth: A new framework and some evidence from cross-section and time-series data. American Economic Review, 76(1), 191–203] to construct the threshold regression model. Three classifications of government size are tested in sequence as threshold variables. The result indicates that all three classifications of government size have a threshold effect and that a non-linear relationship of the Armey curve exists in Taiwan.     

什么决定了企业的最佳规模?——关于企业规模的研究述评

企业规模问题是企业理论中的焦点问题,通过从市场范围、生产要素、交易费用、产权、激励成本和信息成本等六个方面综合考察决定企业规模的因素以及相应的实证研究结果,指出了关于企业规模的企业理论对企业并购的理论启示和现实意义,并展望了今后的研究前景。