The moments of the Gompertz distribution and maximum likelihood estimation of its parameters

The Gompertz distribution is widely used to describe the distribution of adult deaths. Previous works concentrated on formulating approximate relationships to characterise it. However, using the generalised integro-exponential function, exact formulas can be derived for its moment-generating function and central moments. Based on the exact central moments, higher accuracy approximations can be defined for them. In demographic or actuarial applications, maximum likelihood estimation is often used to determine the parameters of the Gompertz distribution. By solving the maximum likelihood estimates analytically, the dimension of the optimisation problem can be reduced to one both in the case of discrete and continuous data. Monte Carlo experiments show that by ML estimation, higher accuracy estimates can be acquired than by the method of moments.     

Modeling and Measuring Economic Reality: Reply to the Reviews

To begin with, we'd like to express our appreciation to our three commentators for their thoughtful and helpful reviews. Like the founders of the subject, we believe, and our reviewers seem to agree, that structural econometrics has the potential to enable us to develop serious working models of how different economies actually operate, and also to tell us something about the changing patterns of their growth and transformation. But both we and our reviewers agree that there is a great deal wrong with the way econometrics is practiced today.     

苏里格气田苏X区盒8段储层测井二次解释及应用

就苏里格气田苏X区盒8段储层测井二次解释进行了研究。在阐述测井资料预处理的基础上,对储气层孔隙度解释、渗透率解释、泥质含量解释、含气饱和度解释的模型与有效厚度下限的确定作了论述。     

Beyond Asymmetry: Substantive Beliefs in Preference Formation and Efficiency of Asymmetrical Negotiations

Contrary to extant propositions on the primacy of trade dependency in compelling faster agreement by subordinate states in asymmetrical economic negotiations, in the European Union–Africa, Caribbean and Pacific (EU–ACP) Economic Partnership Agreement (EPA) negotiations, it is the states that were least materially vulnerable that were quickest to accept an EPA. Why so? I argue that the speed and propensity of ACP states to accept and ratify their EPAs were principally hinged on variances in preference formation based on what Ikenberry and Kupchan [(1990), ‘Socialization and Hegemonic Power’, International Organization, 44 (3), pp. 283–315: 283] call ‘substantive beliefs rather than material payoffs’. The quickest states to ratify an EPA were those which most intensely shared the EU's neoliberal belief in an automatic correlation between trade liberalisation and economic growth, rather than those that were most materially vulnerable. Therefore, by taking the normative sources of preference formation by subordinate states seriously, we can not only derive a parsimonious explanation of EPA negotiating efficiency but also form a foundational conceptual model of predicting efficiency in asymmetrical negotiations that unifies the role of both normative and material considerations.     

The Sexual Economy,Gender Relations and Narratives of Infant Death on a Tomato Farm in Northern South Africa

Based on an extended case study of a large‐scale tomato farm in northern Limpopo province, the paper examines how the restructuring of agriculture transforms the sexual economy through shifts in the composition of labour and management practices on farms in this area. The employment of Zimbabwean migrants, rather than relatively permanent Venda families, suggests a potentially greater variety of people participating in the sexual economy. While families as units of employment have declined, black supervisors increasingly serve as a primary locus of coercion on the farm and in the sexual economy. The monetization of erstwhile paternalistic services places pressure on women to earn income however they can, including transactional sex. Contested interpretations over the causes of infant deaths on the farm, in the form of hygiene, blood‐mixing and infanticide, provide an ethnographic framework for a deeper analysis of the sexual economy and its social effects. While the sexual economy presents opportunities for women to increase their income, it also exposes them to the risks of HIV/AIDS and unwanted pregnancies, resulting in contradictory implications for the status of women on farms.     

Local Powers of Optimal One‐sample and Multi‐sample Tests for the Concentration of Fisher‐von Mises‐Langevin Distributions

One‐sample and multi‐sample tests on the concentration parameter of Fisher‐von Mises‐Langevin distributions on (hyper‐)spheres have been well studied in the literature. However, only little is known about their behaviour under local alternatives, which is due to complications inherent to the curved nature of the parameter space. The aim of the present paper therefore consists in filling that gap by having recourse to the Le Cam methodology, which has recently been adapted from the linear to the spherical setup. We obtain explicit expressions of the powers for the most efficient one‐ and multi‐sample tests. As a nice by‐product, we are also able to write down the powers (against local Fisher‐von Mises‐Langevin alternatives) of the celebrated Rayleigh test of uniformity. A Monte Carlo simulation study confirms our theoretical findings and shows the empirical powers of the above‐mentioned procedures.     

多层微波集成电路中微带线层间互连仿真

针对多层微波集成电路设计的微带线层间互连问题，介绍了垂直通孔互连、垂直带条互连和层耦合过渡互连三种高性能的互连方法，并且采用三维电磁仿真软件HFSS对这三种互连结构进行了建模和仿真。仿真结果表明，垂直通孔互连和垂直带条互连在0.1～25 GHz的频宽范围内，回波损耗S11<-20 dB，插入损耗S21>-1 dB，互连性能优良，而层耦合过渡互连在20～68 GHz内回波损耗S11 <-20 dB，插入损耗S21>-1 dB，具有在毫米波频段实现互连的潜力。     

The Corporate Side of the Blogosphere: Examining the Variations of Design and Engagement Among Fortune 500 Blogs

Using design and communication principles, this study uses a content analysis design to evaluate all active blogs from the 2011 Fortune 500 list (n = 125). The results indicate that corporate America has only modestly incorporated the dialogic principles into their blogs. Current corporate blogs are well-designed as far as making them searchable and easy to navigate; however, the blogs are mostly being used to provide information in a one-way manner rather than creating an open dialogue with consumers. While blogging can enhance relationships with stakeholders, corporate communicators must strive to develop legitimate conversations with their blog readers.     

International free riding on institutions

Economic institutions are linked to economic growth because they create conditions favourable for production and exchange. Institutions can give a country comparative advantage in producing some goods. If its trading partners lack such institutions, it can still enjoy their benefits by importing these goods. Some institutions, such as intellectual property rights, have non‐excludable benefits because the resulting production is intangible, non‐rival, and often publicly disclosed. The profits, or surplus, that result, however, is rival. Foreign countries can ‘free ride’ on this benefit by misappropriating rival surplus through infringement. This article develops a theory of institutional free riding in which firms in one country free ride on the benefit of foreign institutions to the detriment of their competitor firms and their countries' institutions. It evaluates the incentives of firms and governments for this free riding, its effects, and potential responses to mitigate these effects.     

The legitimacy of subsidiary issue selling: Balancing positive & negative attention from corporate headquarters

We consider how in issue selling, subsidiaries draw on different forms of legitimacy to attract corporate headquarters’ (CHQ) positive attention and minimise negative CHQ attention. Through case study evidence, we find that directing CHQ attention to subsidiary issues needs to be executed as a balancing act through forms of subsidiary legitimacy, namely; the personal legitimacy of key individuals at the subsidiary; consequential legitimacy vis-à-vis peer subsidiaries; and linkage legitimacy in the local environment. We develop a typology of subsidiary issue-selling roles and illustrate how negative CHQ attention results from a failure to legitimise issue selling.