Statistical efficiency in the linear combination of forecasts

In seeking an efficient combination of forecasts which minimises the forecast error variance, many methods have been suggested. Through analysis, simulation and case studies, this paper seeks to develop insights into the statistical circumstances which influence the relative accuracy of six of these methods. The six methods chosen have all been advocated in various publications and consist of ‘equal weighting’ (i.e., pooled average), ‘optimal’ (i.e., error variance minimising), ‘optimal with independence assumption’ (i.e., error variance minimising assuming zero correlation between individual forecast errors) and three variations on the formulation of a Bayesian combination based upon posterior probabilities. The statistical circumstances reflected varying conditions of relative forecast errors, error correlations and outliers.     

上市公司并购的股价效应——来自2007年沪深A股市场的经验证据

采用有双变量GARCH模型进行修正过的事件研究方法,对2007年中国沪、深两市51起代表性并购事件进行实证研究.结果表明,在短期内,并购能给目标公司带来显著的价值增值,但在长期内并不明显;并购公司不同并购策略能给目标公司带来不同的影响;经营业务专业化与区域位置集中化类型的并购使目标公司价值增大的概率较大.     

Thought experiments, counterfactuals and comparative analysis

This article discusses the problem of “thought experiments” in Austrian economics and takes as a starting point Lawrence Moss’ argument on the divide between the older Austrian economists—for whom thought experiments were crucial—and the new generation that, in Moss’ view, has “abandoned” such methods. The article is an attempt not only to bridge this alleged divide but also to contribute to the development of the Austrian methodology. It is argued that what may be perceived as “abandonment” bolsters rather than precludes the role of thought experiments in the Austrian paradigm. The article identifies an entire family of comparative and counterfactual analysis research strategies available to the Austrians, all enjoying a solid epistemological and methodological grounding. The “comparative-counterfactual analytics” pattern threads together the conjectural histories, spontaneous orders and empirical case studies of the contemporary Austrians, with the classic tradition of older works. Consequently, the recent evolution of Austrian scholarship should not be seen as an aberration or abandonment but as a deliberate, natural and commendable development.

“国家创新系统”方法论的讨论

为什么有的国家取得了技术创新、经济发展的巨大成功,而另外一些国家却遭遇到种种困难？国家创新系统的提出便是为了研究解决这一问题的。本文从国家创新系统的提出,它的政策功能以及国家间的比较研究等方面讨论了国家创新系统作为方法论的重要意义。     

我国上市公司高送转公告效应的实证研究

为检验上市公司定高送转预案公告发布对其股票价格的影响,本文以2009年至2010年沪深两市推出高送转预案的285家上市公司为样本,选取公告日前10日至公告日后20日为事件窗口,运用事件研究法对高送转公告效应进行实证研究。结果表明：中国股市具有明显的高送转公告效应,上市公司高送转预案公告发布前后股票具有显著的正价格效应,会产生持续的累计异常正收益;然而,由于信息不对称,部分投资者通常会提前获得有关高送转的内幕信息并提前买入,并以此获得可观的超额收益,而普通投资在公告发布后买入只能获得小部分的超额收益并且需要承担更大的风险。     

交易成本经济学建模问题探讨

交易成本经济学由于缺乏合适的数理模型而饱受批评,所以建模问题是交易成本经济学迫切需要解决的问题。文章分析了交易成本经济学从简化模型到结构模型的发展,同时指出了交易成本经济学在建模方面存在的实际困难和可能的发展方向。     

The state of future in international relations

This paper elaborates the state of Future in International Relations from a comparative theoretical perspective with regard to the selected methodological tools of Futures Studies. It, first, looks into the development of International Relations and Futures Studies to point out, how their contextual, conceptual and epistemological similarities and dissimilarities emerged in due course. It, then, analyses to what extent the methodological differences between selected Futures Studies techniques (e.g. forecasting, trend analysis, Delphi, backcasting, causal layered analysis and integral futures approach) intersect with the conceptual and normative differences between contemporary theories of International Relations stemming from Realism, Liberalism, Constructivism, Post-structuralism, Normative Theory and Critical Theory. The paper characterizes the relevant futures techniques with reference to the theories of International Relations, and scrutinizes selected futuristic narratives of International Relations from a methodological perspective. It, then, elaborates how Futures Studies and International Relations can benefit from each other’s strengths in terms of their methodologies and assumptions. The article finally explores to what extent the promises of Futures Studies techniques conjure up a convergence between different theories of International Relations.     

A bibliometric account of the evolution of EE in the last two decades: Is ecological economics (becoming) a post-normal science?

In ecological economics the debate on formalism and formalization has been addressed in the context of a lively discussion on ecological economics as a ‘post-normal’ (versus ‘normal’) science. Using ecological economics (EE) as a ‘seed’ journal and applying bibliometric techniques to all (2533) the articles published in EE from January 1989 to December 2009, we analyze the evolution of the field of ecological economics aiming to shed light on this debate. We observe the predominance (and increased relevance) of certain research topics: ‘Methodological issues’, ‘Policies, governance and institutions’ and ‘Valuation’. Moreover, ‘Collective action’, ‘Technical change and the environment’ and ‘Values’ stand as emergent themes of research. Finally, we note that ecological economics experienced an ‘empirical turn’ reflected in a shift away from exclusively formalized papers towards exclusively empirical and, to a larger extent, ‘formal and empirical’ ones. The combination of the prominent and emergent topics and the ‘empirical turn’ mirrors the increasing awareness among researchers in the field of the need to address a key specificity of ecological economics — the interdependence of the economic, biophysical and social spheres. On this basis, we argue that at least through the lens of EE, ecological economics has evolved towards a post-normal science.