农业集约化对产权制度和价格体系的依赖性

关于农业集约化的研究始自马克思,由来已久,观点各异。在比较中外学术界关于集约化概念的5种界定之后,依据语义辨析,揭示出英文中的Intensive在汉语中的农学释义为集约的,作为一般形容词为密集的,但中文中的密集与集约却是两种不同的意义。据此,对农业集约化概念予以分类,在分析诸多观点差异的基础上,给出一个新的依赖于产权制度和价格体系的集约化界定,探索资源稀缺性导致的产权制度安排和市场价格体系决定着经济增长由粗放向集约转轨的历史必然性。     

The L2 Rate of Convergence for Event History Regression with Time-dependent Covariates

Consider repeated events of multiple kinds that occur according to a right-continuous semi-Markov process whose transition rates are influenced by one or more time-dependent covariates. The logarithms of the intensities of the transitions from one state to another are modelled as members of a linear function space, which may be finite- or infinite-dimensional. Maximum likelihood estimates are used, where the maximizations are taken over suitably chosen finite-dimensional approximating spaces. It is shown that the L ₂ rates of convergence of the maximum likelihood estimates are determined by the approximation power and dimension of the approximating spaces. The theory is applied to a functional ANOVA model, where the logarithms of the intensities are approximated by functions having the form of a specified sum of a constant term, main effects (functions of one variable), and interaction terms (functions of two or more variables). It is shown that the curse of dimensionality can be ameliorated if only main effects and low-order interactions are considered in functional ANOVA models.     

要素密集度视角下中国与“一带一路”沿线国家贸易合作潜力及提升路径研究——基于254种产品贸易的证据

十年来,“一带一路”已成为新时代中国对外贸易合作的新亮点。文章基于新经济地理学理论,以“一带一路”沿线60个国家为研究样本,利用2001—2019年跨国面板数据,从空间视阈运用动态空间面板随机前沿模型检验了要素禀赋对中国与“一带一路”沿线国家贸易合作的影响效应,在此基础上分析了中国与“一带一路”国家贸易合作效率的变化特征,并分析了不同类别商品贸易的合作潜力,进而结合二维矩阵思想依据要素禀赋和贸易潜力的适配性提出未来释放贸易合作潜力的路径。研究结论表明:基于互联互通指数构建空间互联互通矩阵,检验发现中国与“一带一路”沿线国家贸易合作存在时间—空间双重正向依存关系,自然资源要素和资本要素对中国与“一带一路”沿线国家贸易合作具有显著促进作用,而劳动力要素方面存在一定“竞争关系”,创新要素的贸易促进效应尚未充分发挥。在控制变量方面,东道国经济规模、工业化程度、城镇化水平、两国间存在共同边界、签订协议和加入世界贸易组织贸易均有利于中国与“一带一路”国家间贸易合作,地理距离仍然是阻碍双边贸易合作的重要因素。除此之外,双边贸易合作还会受到非效率因素的影响,中国与“一带一路”沿线国家间贸易合作尚有较大拓展潜力,以上结论经过贸易距离矩阵和经济地理矩阵稳健性检验后依然成立。在异质性方面,进一步发现中国与“一带一路”沿线国家贸易合作存在明显产品异质性特征。在贸易效率方面,中国与“一带一路”沿线国家贸易合作效率不断提升,尚未达到“最优状态”。从贸易潜力层级看,再造型贸易伙伴数量最少,成长型贸易伙伴居多,不同类别产品贸易潜力层级结构呈现非均衡结构特征。最后,结合二维矩阵思想,依据要素禀赋与贸易潜力的适配性,可将贸易伙伴划分为集约高效型、效率引领型、稳步提升型和规模扩张型四类贸易伙伴,在此基础上提出单边突破式、扬优补短渐进式和跨越式三种贸易潜力释放路径,为促进“一带一路”实现“贸易畅通”,高质量推动共建“一带一路”提供重要参考和借鉴。     

Parameter estimation in an alternating repair model

The Weibull intensity is often used in survival analysis of technical products, it is an extremely important intensity to characterize the probabilistic behavior of a large number of real phenomena. This intensity is especially useful as a failure model analyzing the reliability of different types of systems. In this paper we develop statistical methods for an alternating repair model using Weibull intensity. The maximum likelihood estimator is considered for determining the estimations of the model parameters. The distribution of the life times after perfect repairs and imperfect repairs are obtained. The estimation of the Fisher information matrix is given. Simultaneous confidence regions based on the likelihood ratio statistics are developed for the estimators of the shape and scale parameter of the Weibull intensity. Finally simulation study will be given.     

On the Local Polynomial Estimators of the Counting Process Intensity Function and its Derivatives

Abstract. We consider the properties of the local polynomial estimators of a counting process intensity function and its derivatives. By expressing the local polynomial estimators in a kernel smoothing form via effective kernels, we show that the bias and variance of the estimators at boundary points are of the same magnitude as at interior points and therefore the local polynomial estimators in the context of intensity estimation also enjoy the automatic boundary correction property as they do in other contexts such as regression. The asymptotically optimal bandwidths and optimal kernel functions are obtained through the asymptotic expressions of the mean square error of the estimators. For practical purpose, we suggest an effective and easy‐to‐calculate data‐driven bandwidth selector. Simulation studies are carried out to assess the performance of the local polynomial estimators and the proposed bandwidth selector. The estimators and the bandwidth selector are applied to estimate the rate of aftershocks of the Sichuan earthquake and the rate of the Personal Emergency Link calls in Hong Kong.     

西部大开发战略下的成渝经济区研究——基于城市流强度模型

城市流强度是表征城市对外服务功能的量化指标,它描述了城市对外联系的强弱。在西部大开发战略不断深入的宏观背景下,以即将上升为国家战略区域规划的成渝经济区为例,运用城市流强度的方法对区域内主要城市间的空间相互作用、城市流强度及其结构进行系统分析。成渝经济区内各城市的联系地位表现为：高城市流强度值城市为重庆和成都,是区域经济集聚和扩散的中心;中城市流强度值城市为德阳、绵阳、资阳、自贡、南充、达州、广安等7个城市,是区域次级辐射中心;低城市流强度值城市为眉山、遂宁、乐山、雅安、泸州、内江、宜宾等7个城市,为地方集聚和辐射中心。最后提出加强区域内城市联系的简要建议,以期加快成渝经济区的发展与壮大。     

基于不公平厌恶或地位追求的创新顾客最优合同类型研究

本文首先从创新顾客的公平偏好程度、薪酬合同类型（最优激励系数）与激励机制效果的关系入手,引入公平偏好理论（不公平厌恶和地位追求）、相对绩效评估（RPE）和参与成本要素,构建顾客参与企业新产品开发的激励模型;其次,通过模型求解和分析,探讨分析各类薪酬合同中风险成本、不公平预期损失和激励效果之间的关系;最后,通过仿真实验验证并确定企业采用的创新顾客最优薪酬合同类型。研究发现：在同一薪酬合同下,创新顾客愈不在意其参与成本的投入,该合同的激励效果愈积极;关于创新顾客最优合同类型的选择,意味着求解一个三方面权衡,包括风险成本、不公平预期损失和公平偏好的激励效果;对于公平偏好程度较低的创新顾客,企业可采用相对绩效合同,例如锦标竞争合同;对于公平偏好程度较高的创新顾客,当其风险规避程度较高时,可采用团队报酬合同,当其风险规避程度较低时,可采用完美团队合同。     

Antecedents and Outcomes of Political Tie Intensity: Institutional and Strategic Fit Perspectives

Although international nonmarket strategy research has highlighted the importance of political ties, it is still unclear why some foreign subsidiaries are more politically active than others and what conditions may render political practices beneficial in a host country. We argue that foreign subsidiary political tie intensity—the extent to which senior managers provide time and resources in informally dealing with government officials for nonmarket purposes—will be influenced by political institutions in their parent's home country, especially when the MNE parent attempts to protect foreign subsidiary resources. Additionally, we assert that fit between a parent's home country political institutions and foreign subsidiary political tie intensity will positively affect subsidiary performance. We employ primary data collected from 181 foreign subsidiaries in the Philippines and find support for our hypotheses. This study advances international nonmarket strategy research by highlighting how an MNE's home country political institutions shape subsidiary political networking and strategic performance outcomes in host country environments.     

Loudness registers: Normalizing cosmopolitan identities in a narrative of ethnic othering

An analysis of one narrative shows how loudness of voice acquires indexical meaning in interaction and becomes a resource for the narrator to position himself along an axis of social differentiation defined in terms of morality. The narrative was collected among young, male, migrant hip hop artists in Delhi who experienced ethnic othering. In the narrative, loudness registers are used to establish voice contrasts between two antagonistic characters: the racist people of Delhi and the cosmopolitan hip hop self. The racist people speak in soft (piano) and loud (forte) registers, while the cosmopolitan self speaks in normal‐volume registers. The prosodic normalization of the self allows the narrator to differentiate himself from racist others, take moral stances on global solidarity, and construct his cosmopolitan identity.     

Resampling schemes with low resampling intensity and their applications in testing hypotheses

The paper explores statistical features of different resampling schemes under low resampling intensity. The original sample is considered in a very general framework of triangular arrays, without independence or equally distributed assumptions, although improvements under such conditions are also provided. We show that low resampling schemes have very interesting and flexible properties, providing new insights into the performance of widely used resampling methods, including subsampling, two-sample unbalanced permutation statistics or wild bootstrap. It is shown that, under regularity assumptions, resampling tests with critical values derived by the appertaining low resampling procedures are asymptotically valid and there is no loss of power compared with the power function of an ideal (but unfeasible) parametric family of tests. Moreover we show that in several contexts, including regression models, they may act as a filter for the normal part of a limit distribution, turning down the influence of outliers.