外出创业经历能提升返乡创业企业的经营绩效吗?———基于2139家返乡创业企业的调查数据

本文基于2019年北京师范大学劳动力市场研究中心开展的2139家返乡创业企业的调查数据,采用多重中介效应模型,研究创业者外出创业经历对其返乡创业企业经营绩效的影响及其微观作用机制。研究发现,创业者外出创业经历能够显著提升返乡创业企业的经营绩效;外出创业经历能够提升创业者的管理经验,扩大创业者的社会关系网络,有利于创业者获得更多的政策扶持,间接提升返乡创业企业的经营绩效。基于上述结论,建议地方政府积极吸引具有外地创业经历的企业家返乡创业,加大对返乡创业者的创业培训,提高返乡创业者的管理能力,支持创业者培育社会关系网络,加大返乡创业扶持政策的宣传,提升小微企业的经营绩效,助力乡村振兴。     

A consistent parameter estimation in the three-parameter lognormal distribution

In this work, we propose a consistent method of estimation for the parameters of the three-parameter lognormal distribution. We then discuss some properties of these estimators and show by means of a Monte Carlo simulation study that the proposed estimators perform better than some other prominent estimators in terms of bias and root mean squared error. Finally, we present two real-life examples to illustrate the method of estimation proposed.     

流转税和所得税的福利效应研究

 本文根据我国城市（镇）不同收入阶层1999年至2008年的支出结构数据及现金收入和支出统计状况,测算出我国城镇居民消费支出的有效税率②和所得税额;利用跨期消费决策的两期模型,构造居民消费效用函数,即消费者的福利函数,测算出我国流转税和所得税的福利损失（成本）。结果显示：我国居民消费符合边际消费倾向递减规律;不同收入阶层的消费时间偏好不同,收入水平越低越倾向于当前消费;流转税具有明显的累退效应,而所得税的累进效应,特别是个人所得税的累进效应不明显,使得我国当前的税制结构对收入分配的调节力度不够。     

大学生就业决定因素分析——基于多层模型的方法

本文利用山东2007届高校毕业生就业调查数据,建立多层交叉随机效应模型,检验了个体、专业和学校等多层变量对大学生就业的影响。结果发现,初次就业概率在学校和专业之间存在显著差异,且学校因素对就业的作用大于专业,但学校与专业对就业的交互作用不显著。就业能力以及与专业相关的实习经历对就业具有显著的正向作用。因此,大学生就业政策的重点是提高教育质量和突出专业特色,提升就业能力,完善就业导向的实习指导和服务。     

投资率门限特征、消费促进与经济增长：1995-2007

 目前,国际经济形势欠佳,出口市场严峻,拉动内需成为我国经济工作重点,投资与消费的关系再次受到学界关注。本文阐述了投资率和消费率协调统一的关系,并运用1995-2007年中国省区面板数据,根据投资率的门限特征进行非线性回归。分析结果表明,投资率主要存在两个门限值,第一个门限值位于44%,在该值以下,消费率的提高显著促进了经济增长;第二个门限值为36%左右,在该值以下,消费率的提高进一步拉动经济增长速度。然而,单纯依靠消费需求拉动将导致投资不足的“陷阱”,为此,本文提出了两项政策建议：挖掘可极大拉动第二产业增长的新消费点;在东部和中西部之间实现有所差异的战略布局。     

低生育率水平下人口发展的经济后果分析

本文分析了低生育率水平下人口发展对未来我国经济发展的积极影响 ,同时指出它是一把双刃剑 ,同样也有不利于经济发展的后果。为了既充分发挥低生育水平的积极作用 ,又逐步消除或缓解其不良后果 ,一方面要适时地调整现行生育政策 ,选择适当的总和生育率水平 ,另一方面要构建相应的政策支持体系予以支撑。     

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.     

Formulas for the Design of CUSUM Quality Control Charts

ABSTRACT

In the design of CUSUM control charts, it is common to use charts, tables, or software to find an appropriate critical threshold (h). This article provides an approximate formula to calculate the threshold directly from prespecified values of the reference value (k) and the in-control average run length (ARL₀). Formulas are also provided for choosing k and h from prespecified values of the in-control and out-of-control average run lengths.     

Estimation of the Proportion of Defective Units by Using Group Testing Under the Existence of a Threshold of Detection

Group testing procedures, in which groups containing several units are tested without testing each unit, are widely used as cost-effective procedures in estimating the proportion of defective units in a population. A problem arises when we apply these procedures to the detection of genetically modified organisms (GMOs), because the analytical instrument for detecting GMOs has a threshold of detection. If the group size (i.e., the number of units within a group) is large, the GMOs in a group are not detected due to the dilution even if the group contains one unit of GMOs. Thus, most people conventionally use a small group size (which we call conventional group size) so that they can surely detect the existence of defective units if at least one unit of GMOs is included in the group. However, we show that we can estimate the proportion of defective units for any group size even if a threshold of detection exists; the estimate of the proportion of defective units is easily obtained by using functions implemented in a spreadsheet. Then, we show that the conventional group size is not always optimal in controlling a consumer's risk, because such a group size requires a larger number of groups for testing.     

Statistical Properties of Threshold Models

This article focuses the attention on the Self Exciting Threshold Autoregressive Moving Average model (SETARMA) proposed in Tong (1983 Tong , H. ( 1983 ). Threshold Models in Nonlinear Time Series Analysis . London : Springer-Verlag .[Crossref] , [Google Scholar]). The stochastic structure of the model is discussed and different specifications are presented. Starting from one of them, we give sufficient conditions for the weak stationarity of the model that are discussed and critically compared to other results given in literature. In particular, after showing that the SETARMA model belongs to the class of the Random Coefficients Autoregressive models, widely discussed in Nicholls and Quinn (1982 Nicholls , D. F. , Quinn , B. G. (1982). Random Coefficients Autoregressive Models. An Introduction . New York : Springer-Verlag.[Crossref] , [Google Scholar]), we give some issues on the weak stationarity of its stochastic structure that are more general than those given in the existing literature and appear not affected by the moving average component.