Can the Augmented Solow Model with Migration Explain the Italian Internal Brain Drain?

We extend the Dolado et al. (1994) model to both inflows and outflows of migrants and assume that they have a human capital endowment that contributes to increase/decrease the stock of human capital in the receiving/sending economy. We derive the conditional convergence equation in which the impact of migration flows on the growth rate is disentangled in a pure quantity effect and in a quality or composition effect of immigration and emigration rates that accounts for the relative human capital endowment of migrants with respect to resident population. Next, we test the model with Italian regional data for the 1970–2005 time period. We find that the model provides a good explanation of the Italian experience. The quantity effect is negative for the immigration rate and positive for the emigration rate, whereas the composition effect is positive for immigration and negative for emigration. Finally, we separate the centre‐north from the south and find that the composition effect of emigration is stronger for the latter. We interpret these results as a clear evidence of a brain drain from the Mezzogiorno to the centre‐northern regions.     

R语言在统计学教学中应用初探

在统计学教学中引入一款合适的统计软件就变得尤为重要,而R语言简单易学,统计分析功能强大,正好是统计教学辅助工具的最佳选择.文章通过一个简单的例子,逐步引导学生掌握R语言的应用,解决统计分析中的问题.     

高校科技对区域经济发展贡献率的实证分析

目前,技术进步逐渐成为促进区域经济发展的主要动力,而高校科技是推动我国科技进步的重要力量,它必然会对区域经济发展做出贡献。文章在选择适当计量模型的基础上,就辽宁省高校科技对区域经济发展的科技进步率和科技进步贡献率进行了实证分析。研究表明,高校的研发支出效率远高于其他科研机构的平均水平,高校科技对地方经济增长具有重大的推动作用。所以,应加大对高等院校科技投入,提高研发投入效率,以达到促进区域经济快速发展的目的。     

研发网络架构与网络价值：综述及概念模型

本文聚焦于企业的研发网络,通过综述企业研发网络架构方面的相关文献,识别出研发网络架构的三大维度（网络成员组合、网络结构属性及网络关系特征）及其主要内容,并基于此分析了中心企业的研发网络架构对该网络的网络价值的影响机制。结合企业战略目标及具体诉求及企业外部环境的权变影响,本文提出了一个围绕网络价值最大化命题,以研发网络架构为基点、网络价值为终点的理论研究框架,讨论了现有研究结论及未来可能的研究,为中心企业选择研发合作伙伴、配置网络成员、部署网络结构及管理成员关系提供借鉴。     

从统计学史解析“自由度”概念

自由度是统计学中一个十分重要而又长期没有被圆满解释的概念。对此,从统计学史角度,对皮尔逊、费歇尔有关自由度问题争论原始文献细致考察,彻底澄清了自由度概念的内涵及与其相关的统计思想,弥补了Fienberg、Stigler与陈希孺已有解释的缺陷。研究表明：皮尔逊关于卡方检验中无论总体分布已知还是其来自于样本推断统计量都具有同一分布的错误判断,导致卡方检验的准确性出现偏差,这种偏差虽被同时代少数几个统计学家察觉但他们却无法解释其根源。费歇尔提出自由度概念并结合n维几何、假设检验与最大似然方法的论证不仅修正了皮尔逊的错误,也完善了从样本统计量估计总体参数的数理逻辑。     

Credit access,macroprudential rules and policy interventions: Lessons for potential first time buyers

Given the increased popularity of macroprudential measures in the aftermath of the great financial crisis (GFC), a key policy question to arise in certain mortgage markets is whether a significant access to credit issue exists amongst prospective homeowners because of these new policies. In this paper we assess whether such a problem arises in the context of the Irish mortgage market – a market particularly adversely impacted by the GFC. We use a microsimulation model to estimate the level of latent credit demand that could be serviced by the market given prudent credit risk assessment and the current macroprudential regulations. We then compare this demand to current market provision to explore whether a credit gap exists. Finally, we simulate how a public mortgage credit scheme or equity “help-to-buy” type instrument may help credit access. We find both instruments to be effective but would lead to somewhat higher house prices.     

Effects of urbanization on trust: Evidence from an experiment in the field

I conducted a trust game in the field within a natural experiment paradigm to test the effects of urbanization on both in- and out-group trust. I found that urbanization has a larger positive effect on out-group trust than on in-group trust. My findings provide new knowledge to the literature on the intricacy of the urbanization-trust relationship and contribute to the ongoing discourse on the different foundations underpinning in-group and out-group trust.     

Quantal Risk Assessment Database: A Database for Exploring Patterns in Quantal Dose‐Response Data in Risk Assessment and its Application to Develop Priors for Bayesian Dose‐Response Analysis

Quantitative risk assessments for physical, chemical, biological, occupational, or environmental agents rely on scientific studies to support their conclusions. These studies often include relatively few observations, and, as a result, models used to characterize the risk may include large amounts of uncertainty. The motivation, development, and assessment of new methods for risk assessment is facilitated by the availability of a set of experimental studies that span a range of dose‐response patterns that are observed in practice. We describe construction of such a historical database focusing on quantal data in chemical risk assessment, and we employ this database to develop priors in Bayesian analyses. The database is assembled from a variety of existing toxicological data sources and contains 733 separate quantal dose‐response data sets. As an illustration of the database's use, prior distributions for individual model parameters in Bayesian dose‐response analysis are constructed. Results indicate that including prior information based on curated historical data in quantitative risk assessments may help stabilize eventual point estimates, producing dose‐response functions that are more stable and precisely estimated. These in turn produce potency estimates that share the same benefit. We are confident that quantitative risk analysts will find many other applications and issues to explore using this database.