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11.
基于财务柔性组织理论,本文利用2007-2017年我国A股上市非金融类公司微观数据,从理论和实证检验分析了企业财务柔性能力对持续性创新的影响,结果显示企业财务柔性对持续性创新存在正向促进作用。进一步,本文探讨了财务柔性可能存在的“协调创新效应”和“自适应效应”两种机制。协调创新效应相关检验结果显示企业储备的财务柔性能力能有效协调内外部资源,释放融资约束的负向影响,从而正向促进企业持续性创新。检验结果还显示,企业主动地调节财务柔性储备,能够在不同维度环境的不确定性影响下发挥“自适应效应”,助力企业实现持续创新的目标。总体而言,本文结论改善了企业断点式或阶段式的创新投入方式,切实提升了企业自主研发能力和质量,对`实现我国创新“量质平衡”有重要意义。  相似文献   
12.
This article uses Danish register data to explain the retirement decision of workers in 1990 and 1998. Many variables might be conjectured to influence this decision such as demographic, socioeconomic, financial, and health related variables as well as all the same factors for the spouse in case the individual is married. In total, we have access to 399 individual specific variables that all could potentially impact the retirement decision. We use variants of the least absolute shrinkage and selection operator (Lasso) and the adaptive Lasso applied to logistic regression in order to uncover determinants of the retirement decision. To the best of our knowledge, this is the first application of these estimators in microeconometrics to a problem of this type and scale. Furthermore, we investigate whether the factors influencing the retirement decision are stable over time, gender, and marital status. It is found that this is the case for core variables such as age, income, wealth, and general health. We also point out the most important differences between these groups and explain why these might be present.  相似文献   
13.
A fully nonparametric model may not perform well or when the researcher wants to use a parametric model but the functional form with respect to a subset of the regressors or the density of the errors is not known. This becomes even more challenging when the data contain gross outliers or unusual observations. However, in practice the true covariates are not known in advance, nor is the smoothness of the functional form. A robust model selection approach through which we can choose the relevant covariates components and estimate the smoothing function may represent an appealing tool to the solution. A weighted signed-rank estimation and variable selection under the adaptive lasso for semi-parametric partial additive models is considered in this paper. B-spline is used to estimate the unknown additive nonparametric function. It is shown that despite using B-spline to estimate the unknown additive nonparametric function, the proposed estimator has an oracle property. The robustness of the weighted signed-rank approach for data with heavy-tail, contaminated errors, and data containing high-leverage points are validated via finite sample simulations. A practical application to an economic study is provided using an updated Canadian household gasoline consumption data.  相似文献   
14.
李毅等 《统计研究》2019,36(4):95-105
随着大数据背景下抽样环境复杂化,特别是3S技术(遥感技术、地理信息系统和全球定位系统)日趋成熟,越来越多社会经济问题涉及空间抽样,其样本呈现出规模相对稀少、分布不均匀、局部聚集的特征,使得传统抽样调查面临着严重挑战。本文介绍了适应性抽样技术应用于空间网络环境的基本原理、主要操作步骤和马尔可夫链蒙特卡罗估计推断,并以广州市天河区的商户抽样为例讨论实际操作中应注意的问题,以期为流动人口、环境污染、区域经济研究等方面调查提供理论支撑和实证方法参考。  相似文献   
15.
We compare posterior and predictive estimators and probabilities in response-adaptive randomization designs for two- and three-group clinical trials with binary outcomes. Adaptation based upon posterior estimates are discussed, as are two predictive probability algorithms: one using the traditional definition, the other using a skeptical distribution. Optimal and natural lead-in designs are covered. Simulation studies show that efficacy comparisons lead to more adaptation than center comparisons, though at some power loss, skeptically predictive efficacy comparisons and natural lead-in approaches lead to less adaptation but offer reduced allocation variability. Though nuanced, these results help clarify the power-adaptation trade-off in adaptive randomization.  相似文献   
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《逻辑哲学论》中的神秘主义是前期维特根斯坦的重要思想之一。西方学者对这一思想的具体内容以及它同《逻辑哲学论》中其他思想之间的关系评价不一,而且这些评价都有自身的局限性。事实上,如果从全局的视域来考察《逻辑哲学论》就会发现,通往神秘主义有两条路径:一条是语言哲学的路径;另一条是逻辑哲学的路径。神秘主义是维特根斯坦对有意义的科学命题和缺少意义的逻辑命题进行分析所推导出的一个逻辑结论,它与《逻辑哲学论》中的图像论和逻辑哲学是一个不可分割的整体,这种整体性表明维特根斯坦力图实现经验的自然科学、先验的逻辑学和超验的伦理学的统一。  相似文献   
18.
通过文献分析和定量分析,认为在小城镇的建设进程中,应以产业发展为支撑,尤其应注重产业的聚集问题研究。应用复杂适应系统理论基于StarLogo平台对西部小城镇的产业集聚进行建模与仿真,通过对产业集聚障碍成因的剖析明晰西部小城镇建设的进程和路径,并提出相应的政策建议。  相似文献   
19.
Typically, parametric approaches to spatial problems require restrictive assumptions. On the other hand, in a wide variety of practical situations nonparametric bivariate smoothing techniques has been shown to be successfully employable for estimating small or large scale regularity factors, or even the signal content of spatial data taken as a whole.We propose a weighted local polynomial regression smoother suitable for fitting of spatial data. To account for spatial variability, we both insert a spatial contiguity index in the standard formulation, and construct a spatial-adaptive bandwidth selection rule. Our bandwidth selector depends on the Gearys local indicator of spatial association. As illustrative example, we provide a brief Monte Carlo study case on equally spaced data, the performances of our smoother and the standard polynomial regression procedure are compared.This note, though it is the result of a close collaboration, was specifically elaborated as follows: paragraphs 1 and 2 by T. Sclocco and the remainder by M. Di Marzio. The authors are grateful to the referees for constructive comments and suggestions.  相似文献   
20.
We consider the situation where one wants to maximise a functionf(θ,x) with respect tox, with θ unknown and estimated from observationsy k . This may correspond to the case of a regression model, where one observesy k =f(θ,x k )+ε k , with ε k some random error, or to the Bernoulli case wherey k ∈{0, 1}, with Pr[y k =1|θ,x k |=f(θ,x k ). Special attention is given to sequences given by , with an estimated value of θ obtained from (x1, y1),...,(x k ,y k ) andd k (x) a penalty for poor estimation. Approximately optimal rules are suggested in the linear regression case with a finite horizon, where one wants to maximize ∑ i=1 N w i f(θ, x i ) with {w i } a weighting sequence. Various examples are presented, with a comparison with a Polya urn design and an up-and-down method for a binary response problem.  相似文献   
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