Hierarchies and entrepreneurship

We establish a correlation between the hierarchical structure of a firm and the likelihood of business creation among its former employees, using a sample of 16 million observations of Swedish workers and a novel proxy for hierarchies based on occupation data. Conditional on firm size and many other variables, employees in firms with more layers are less likely to enter entrepreneurship, to become self-employed, and to switch to another employer. The effects of layers are much stronger for business creation than for job-switching and they are stronger for entrepreneurship than for self-employment. We discuss two potential explanations for the distinctive hierarchy effect we find. Part of the effect could be to be due to preference sorting by employees, and part due to employees in firms with fewer layers having a broader range of skills. One test showing that the probability of entrepreneurship increases with their prior rank in an organization is consistent with ability sorting and inconsistent with preference sorting.     

Co‐movements in commodity prices: a note based on network analysis

This article analyses co‐movements in a wide group of commodity prices during the time period 1992–2010. Our methodological approach is based on the correlation matrix and the networks inside. Through this approach we are able to summarize global interaction and interdependence, capturing the existing heterogeneity in the degrees of synchronization between commodity prices. Our results produce two main findings: (a) we do not observe a persistent increase in the degree of co‐movement of the commodity prices in our time sample, however from mid‐2008 to the end of 2009 co‐movements almost doubled when compared with the average correlation; (b) we observe three groups of commodities which have exhibited similar price dynamics (metals, oil and grains, and oilseeds) and which have increased their degree of co‐movement during the sampled period.     

Structuring an effective human error intervention strategy selection model for commercial aviation

Flight safety cannot be compromised. Thus, commercial airlines should constantly develop safety management strategies to mitigate the diverse hazardous factors in flight operations. Given the constraint of organizational resource, a commercial airline may not have sufficient resources to implement all the necessary strategies simultaneously. This study uses a well-structured process to develop a qualitative evaluation model that will enable airlines to identify human errors and select an intervention strategy with the highest success potential. To clarify the decision problem, the Human Factors Intervention Matrix framework is utilized to construct the decision hierarchy. The Analytic Hierarchy Process is then used to attain the priorities of potential alternative strategies for various unsafe acts. Finally, Zero-One Goal Programming models are formulated to select an optimal portfolio based on the specific target and the available organizational resources. An empirical study is presented to illustrate the application of the proposed model. According to the results of the combined model, an optimal portfolio, including the intervention approaches of organizational/administrative, human/crew, and operational/physical environment, can remediate four unsafe acts, namely, decision errors, skill-based errors, perceptual errors, and violations, under resource constraints of the organization.     

Continuity Estimates for Ruin Probabilities

A method of continuity analysis of ruin probabilities with respect to variation of parameters governing risk processes is proposed. It is based on the representation of the ruin probability as the stationary probability of a reversed process. We apply Kartashov's technique designed for continuity analysis of stationary distributions of general Markov chains in order to obtain desired continuity estimates. The method is illustrated by the Sparre Andersen and Markov modulated risk models.     

煤矿开拓方案选择的层次灰关联决策

本文从井巷工程、工业场地、场外公路、主要设备、开拓方式、井筒水文地质、到火车的距离等七个方面建立了煤矿开拓方案评价的指标体系,并利用层次分析法与灰关联决策相结合的方式进行煤矿开拓方案的选择,进而给出煤矿开拓方案选择层次灰关联决策的具体步骤,最后进行实例应用。     

Learning from the implementation of Universal Free School Meals in Scotland using Normalisation Process Theory: Lessons for policymakers to engage multiple stakeholders

In 2014/15, Universal Free School Meals (UFSM) were introduced in Scotland and England for children in their first three years of primary school. This study examined the implementation of UFSM in Scotland using Normalisation Process Theory (NPT), a middle-range theory of implementation, to identify areas of learning for policymakers wishing to introduce or extend similar policies. NPT is predominantly used to evaluate interventions or new technologies in healthcare settings. Qualitative data were collected across Scotland using a case study approach shortly after implementation (n = 29 school-level stakeholders) and in the following school year (n = 18 school-level stakeholders and n = 19 local authority-level stakeholders). Observations of lunchtime in each school were conducted at both timepoints. Data were analysed using a thematic framework approach using NPT constructs and sub-constructs. Results suggested education and catering stakeholders experiences of implementation diverged most around the NPT concepts of coherence, cognitive participation, and reflexive monitoring. Lack of coherence around the purpose and long-term benefits of UFSM appeared to reduce education stakeholders’ willingness to engage with the policy beyond operational issues. In contrast, catering stakeholders identified a direct benefit to their everyday work and described receiving additional resources to deliver the policy. Overall, participants described an absence of monitoring data around the areas of greatest salience for education stakeholders. This study successfully used NPT to identify policy learning around school meals. Policymakers must increase the salience of such intersectoral policies for all relevant stakeholders involved before policy implementation, and plan adequate monitoring to evaluate potential long-term benefits.     

TPS系统参数组态应用示例

分散控制系统DCS在石油和化工生产中应用十分广泛。通过对系统组态使得系统功能得以实现。本文针对TPS系统控制站的常规控制点参数组态进行示例分析,有效解决生产中的实际问题,提高系统实用性。