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1.
We use a unique firm-level data set including 9000 companies from 26 European Union countries covering four different sectors to take a close look at the relationship between online exports and productivity. The online exporter productivity premium is estimated using different techniques (ordinary least squares, quantile regressions and robust estimation). Results consistently indicate that the estimated online exporter productivity premium is statistically different from zero, positive and significant from an economic point of view. European online exporters, according to these results, are approximately 2% more productive than non-online exporters. Productivity differences between firms could be related to variables that are not included in the empirical model. More research would be needed to address this issue in the future.  相似文献   
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传统粒子滤波(PF)直接采用状态转移先验分布作为重要性密度函数来近似后验概率密度函数,使得后验概率密度函数未包含量测信息。针对此问题,提出了一种改进高阶容积粒子滤波(CPF)的系统状态估计算法。算法采用七阶正交容积卡尔曼滤波(7th-CQKF)对PF的粒子进行传递,使得先验分布更新阶段融入最新量测信息;通过7th-CQKF设计重要性密度函数,提高对状态后验概率密度的逼近程度;通过反比例函数计算粒子权重,突出大噪声粒子与小噪声粒子权重差别,提高粒子有效性。仿真结果表明,改进高阶容积粒子滤波的估计精度高于容积粒子滤波(CPF)。  相似文献   
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Unlike most of the literature that examines the relationship between corporate philanthropy and financial performance, this study investigates the mechanisms through which corporate socially responsible behaviors produce financial outcomes. We propose that corporate philanthropy improves corporate competitiveness by eliciting positive responses from stakeholders, who assess a firm’s philanthropic contribution in relation to its rivals to determine what level of support they wish to provide to the firm. We predict that a firm’s philanthropy relative to its rivals has a positive effect on its product market competitiveness, and that this positive effect is moderated by three conditions that influence stakeholder response: stakeholder attention to philanthropy, its perceived legitimacy, and expectations of corporate giving. Our predictions are generally supported by our analyses. Overall, this paper shows that strategic philanthropy has a quantitative dimension, and firms obtain the market competitiveness associated with corporate philanthropy by integrating their rivals’ positions into their decision making.  相似文献   
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The Local Whittle Estimator of Long-Memory Stochastic Volatility   总被引:1,自引:0,他引:1  
We propose a new semiparametric estimator of the degree of persistencein volatility for long memory stochastic volatility (LMSV) models.The estimator uses the periodogram of the log squared returnsin a local Whittle criterion which explicitly accounts for thenoise term in the LMSV model. Finite-sample and asymptotic standarderrors for the estimator are provided. An extensive simulationstudy reveals that the local Whittle estimator is much lessbiased and that the finite-sample standard errors yield moreaccurate confidence intervals than the widely-used GPH estimator.The estimator is also found to be robust against possible leverageeffects. In an empirical analysis of the daily Deutsche Mark/USDollar exchange rate, the new estimator indicates stronger persistencein volatility than the GPH estimator, provided that a largenumber of frequencies is used.  相似文献   
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Price variations at speculative markets exhibit positive autocorrelationand cross correlation. Due to large parameter spaces necessaryfor joint modeling of variances and covariances, multivariateparametric volatility models become easily intractable in practice.We propose an adaptive procedure that identifies periods ofsecond-order homogeneity for each moment in time. To overcomethe high dimensionality of the problem we transform the multivariateseries into a set of univariate processes. We discuss thoroughlythe implementation of the adaptive technique. Theoretical andMonte Carlo results are given. We provide two applications ofthe new method. For a bivariate exchange rate series we comparethe multivariate GARCH approach with our method and find thelatter to be more in line with the underlying assumption ofindependently distributed innovations. Analyzing a 23-dimensionalvector of asset returns we underscore the case for adaptivemodeling in high-dimensional systems.  相似文献   
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This article proposes a new approach to testing for the hypothesisof a single priced risk factor driving the term structure ofinterest rates. The method does not rely on any parametric specificationof the state variable dynamics or the market price of risk.It simply exploits the constraint imposed by the no-arbitragecondition on instantaneous expected bond returns. In order toachieve our goal, we develop a Kolmogorov-Smirnov test and applyit to data on Treasury bills and bonds for both the United Statesand Spain. We find that the single risk factor hypothesis cannotbe rejected for either dataset.  相似文献   
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文章在简要文献回顾基础上,提出了经济发展、环境发展、社会发展三位一体的全面发展竞争力概念与模型.通过指标体系及权重的设计,以全国31个省城为对象进行了比较评价与分析.  相似文献   
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介绍了专利费的特点和测算原则,并对引进的部分专利技术的专利费作了分析和预测。  相似文献   
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