When is dependence on other organizations burdensome? The effect of asymmetric dependence on internet firm failure

Although critical resource providers offer ample access benefits to deficient firms, dependence on these resource providers is burdensome because dependency places deficient firms into a vulnerable position, especially when the dependency is asymmetric. Thus, we ask: Is it better to balance dependence among critical resource providers or asymmetrically depend on one if there is more than one resource provider? We use a unique context of the internet industry where satellite internet firms depend on portals that provide Web traffic and find that asymmetric dependence on portals increases the likelihood of failure, but market leaders suffer less from asymmetric dependence, while satellite internet firms with higher dependence on portals suffer more from asymmetric dependence. Copyright © 2014 John Wiley & Sons, Ltd.     

城市地价空间非平稳格局与测度技术优化应用探索

研究目的：在明晰城市地价空间非平稳格局形成机制的基础上，探索将空间计量经济学前沿技术首次应用于国内地价研究，改进当前常用的地价估计方法及模型，提升地价空间测度的科学性与准确性，为实现对地价空间格局更科学系统的认知及城市空间资源精细化管理提供参考。研究方法：多尺度地理加权回归—空间自回归模型（MGWRSAR模型）。研究结果：（1）区位引导地价形成空间依赖性和异质性非平稳并存的特征。（2）目前既有研究中地价空间格局测度的模型方法未同时考虑两类空间属性参数异构的情况，存在无法测度地价空间依赖强度动态变化的缺陷，模型估计的偏差降低了地价空间研究的准确度。（3）实证结果表明，相较于常用的空间计量模型，MGWR-SAR模型在地价空间非平稳格局测度及决定因素研究中的估计效果更佳。研究结论：未来可采用MGWR-SAR模型提高地价空间测度研究的准确性，并且该模型在其他地理要素空间测度上也具有一定适用性，可为其研究提供技术参考。     

Are Some Forecasters Really Better than Others? A Note*

In this paper, we use bootstrap approach to test the null hypothesis that all forecasters in the U.S. Surveys of Professional Forecasters (SPF) have equal ability. Our bootstrap procedure captures any potential cross-sectional and serial correlation in the forecast errors while preserving the unbalanced nature of the panel data. Once we account for the presence of cross-sectional and serial correlation in the forecast errors while resampling, we find convincing evidence that some individuals really are better than others—this is in sharp contrast to the findings of D'Agostino et al. (2012).