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991.
We develop methods for inference in nonparametric time-varying fixed effects panel data models that allow for locally stationary regressors and for the time series length and cross-section size both being large. We first develop a pooled nonparametric profile least squares dummy variable approach to estimate the nonparametric function, and establish the optimal convergence rate and asymptotic normality of the resultant estimator. We then propose a test statistic to check whether the bivariate nonparametric function is time-varying or the time effect is separable, and derive the asymptotic distribution of the proposed test statistic. We present several simulated examples and two real data analyses to illustrate the finite sample performance of the proposed methods. 相似文献
992.
We analyse whether estimated multiplier effects are systematically higher if the economy suffers a downturn. For that purpose, we conduct a meta‐regression analysis on a unique data set of 98 empirical studies with more than 1800 observations on multiplier effects and control for regime‐dependence of the multiplier. We find that spending multipliers are much higher (by about 0.7–0.9 units) during a downturn. Tax multipliers are not sensitive to the economic regime, and generally lower than spending multipliers. Finally, for all spending categories other than government consumption, the multiplier significantly exceeds one during downturns. 相似文献
993.
Technology‐push,market‐demand and the missing safety‐pull: a case study of American Airlines Flight 587 下载免费PDF全文
Amy L. Fraher 《New Technology, Work and Employment》2015,30(2):109-127
Through a critical case study of the crash of American Airlines Flight 587, this paper draws upon ‘the Social Shaping of Technology’ (SST) approach to offer a reconceptualisation of the technology‐push and market‐demand model for High‐Reliably Organisations (HROs), providing support for a third factor, called here a ‘safety‐pull’. A safety‐pull is defined as organisationally supported reflexivity in which technology innovators and frontline operators collaborate to consider the potential implications of adopting new technologies in HROs and the complex ways this change may impact human operators' work performance, often in risky and unanticipated ways. In contrast to accidents occurring solely as the result of individual operator error, analysing the safety‐pull provides a way to tease out the wide range of factors that can contribute to HRO failures and offers a new SST perspective through which to examine high‐risk operations. 相似文献
994.
《Food Policy》2015
In this article we specify a model of millet prices in the three West African countries of Burkina Faso, Mali, and Niger. Using data obtained from USAID’s Famine Early Warning Systems Network (FEWS NET) we present a unique regional millet price forecasting model that takes advantage of the panel nature of our data and accounts for the distance of rural markets from capital cities. Another novel aspect of our analysis is our use of the Normalized Difference Vegetation Index (NDVI) to detect and control for variation in conditions for productivity. We find that including NDVI information significantly improves price forecasts. 相似文献
995.
Has the “CEO effect” increased in recent decades? A new explanation for the great rise in America's attention to corporate leaders 下载免费PDF全文
We introduce a new explanation for one of the most pronounced phenomena on the American business landscape in recent decades: a dramatic increase in attributions of CEO significance. Specifically, we test the possibility that America's CEOs became seen as increasingly significant because they were, in fact, increasingly significant. Employing variance partitioning methodologies on data spanning 60 years and more than 18,000 firm‐years, we find that the proportion of variance in performance explained by individual CEOs, or “the CEO effect,” increased substantially over the decades of study. We discuss the theoretical and practical implications of this finding. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
996.
萤石的经典分析方法是将碳酸钙和氟化钙分离后,在用滴定法分别进行滴定分析,这种分析方法较为准确,但周期长、效率差、多次滴定易产生误差,无法满足快速大量测定样品的要求。本文探讨通过采用滴定-原子吸收法相结合方式测定萤石中氟化钙、碳酸钙的含量,可在大幅缩短测定时间的同时避免二次滴定产生的误差提升结果准确度,并可用于满足大量萤石样品的分析需求。 相似文献
997.
本文对高速公路互通立交跨线桥的现浇箱梁支架设计方案及验算进行了阐述,主要包括支架布置、支架计算、结果分析等。利用大型有限元分析软件Midas Civil建立模型,对支架的受力、变形及稳定性进行了分析验算,为施工提供了可行依据。 相似文献
998.
999.
建设工程资料是建设工程的重要组成部分,工程资料的管理不仅对建设工程而且对工程后期的使用、维修、改扩建工程有着重要的意义。因此,有必要对工程资料的规范管理及常见问题进行阐述。 相似文献
1000.