中国股市趋向弱势有效之实证研究

本在对中国股票市场有效性的研究结果进行考察的基础上，运用有效市场理论分析了相关研究中存在的问题，最后得出中国股票市场正趋于弱势有效的结论。     

我国股市与货币需求的相互影响分析及政策涵义

运用协整、弱外生性和因果关系检验对我国股票市场与货币需求的关系进行的实证研究发现,股市不影响M2的总量但影响其结构;M1对股市不产生直接影响,而M2对股市的直接影响处于有与无的临界状态;M1、M2均通过GDP对股市产生间接影响,但没有形成利率传导机制,我国股市是关于协整向量的弱外生变量.基于以上结论提出了相应的政策建议.     

The implications,challenges and benefits of a complexity-orientated Futures Studies

Complexity science is increasingly cited as an essential component of a Futures Studies (FS) capable of assisting with the wide-ranging and complex societal problems of the 21st century. Yet, the exact implications of complexity science for FS remain somewhat opaque. This paper explicitly sets out the challenges for FS that arise from six complexity science concepts: (1) irreversibility of time (2) path dependence 3) sensitivity to initial conditions (4) emergence and systemness (5) attractor states (6) complex causation. The discussion highlights the implications of these challenges for FS tools such as horizon scanning and weak signals, and sets out the benefits of overcoming the challenges to create an explicitly complexity-orientated FS. The discussion concludes with a set of questions summarising the challenge for FS from complexity science with the aim of stimulating a discussion as to how they can be met. The concluding remarks make some initial suggestions in this regard.     

Small seeds for grand challenges—Exploring disregarded seeds of change in a foresight process for RTI policy

The recent turn in research, technology and innovation (RTI) policy towards challenge-led strategies is posing new demands to Foresight methodology. RTI Foresight practitioners need to complement their well developed set of technology oriented methods with equally sophisticated approaches tackling societal aspects of innovation. In this paper we aim to make a contribution to this requirement. Building on user innovation theory we argue that demand oriented RTI Foresight needs to systematically integrate voices and hypotheses from the fringes of the innovation system. In order to develop a sound approach for this we set out from well established Foresight theory on “weak signals” and “cognitive biases”. Adopting a constructivist stance towards such signals leads us to the need to set up a socially robust, diverse discourse on “seeds of change hypotheses”. We then outline a practical implementation of such a discourse in the context of the recent Foresight process of the Federal Ministry of Education and Research (BMBF) in Germany. We describe and discuss the experience of this Foresight process and suggest avenues for further development of the approach.     

Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.     

A study of the efficiency of the Chinese clean energy stock market and its correlation with the crude oil market based on an asymmetric multifractal scaling behavior analysis

We examine the multifractal scaling behavior and market efficiency of China’s clean energy stock indexes using an asymmetric multifractal detrended fluctuation analysis (A-MFDFA) and then investigate the tail correlation between this index and the crude oil market via an asymmetric multifractal detrended cross-correlation analysis (A-MFDCCA). First, we reveal that the overall, upward and downward trends of the clean energy stock indexes all have significant multifractal characteristics. The clean energy stock market is far from efficient regardless of whether the fluctuations are small or large. In addition, both upward and downward fluctuations exhibit considerable asymmetry. The significant gap between the downward and overall trends indicates that the downward trend following small-scale fluctuations implies weaker efficiency for investors. Furthermore,based on the sliding market deficiency measure (MDM),we find that the change in efficiency in the three trends significantly depends on the length of the window. In the short term, there is no significant efficiency difference among these three trends; however, in the long term, the asymmetry in the upward and downward trends has gradually increased,especially after December 2018. The results demonstrate that bear markets can offer considerably more opportunities for obtaining excess profits. Finally, we reveal that the cross-correlation between the trends of crude oil prices and low-carbon indexes exhibits significant multifractal characteristics. When the crude oil market is in a bull market or the low-carbon energy market is in a bear market, especially in a larger-scale fluctuation, investors should pay attention to the long-term influence of the counterparty market and carry out a hedging operation to avoid risks.     

How to inhibit a partner's strong and weak forms of opportunism: Impacts of network embeddedness and bilateral TSIs

This study investigates the moderating effects of a firm's network embeddedness and a partner's transactional specific investments (TSIs) on relationships between the firm's TSIs and its partner's strong- and weak-form opportunism, and compares the efficiency among these moderator variables. The regression results suggest that (1) a firm's TSIs are positively related to partner's opportunism when network embeddedness and the partner's TSIs are relatively low; but (2) a firm's TSIs are negatively related to partner's opportunism when network embeddedness and the partner's TSIs are relatively high. Furthermore (3) network embeddedness is more effective in inhibiting partner's weak-form opportunism than in inhibiting strong-form opportunism resulting from the firm's TSIs. Finally (4) with regard to the relationship between TSIs and weak-form opportunism, the negative moderating effect of network embeddedness is greater than the negative moderating effect of partner's TSIs. This study explains reasons why conflicting views exist about the relationship between TSIs and partner's opportunism, reveals the differences in the moderating effects of network embeddedness and partner's TSIs, and makes new contributions to both transaction cost theory and embeddedness literature. It also provides, for firms involved in TSIs in a buyer–supplier relationship, insightful managerial suggestions about ways to reduce their partner's varying forms of opportunism.     

Information in generalized method of moments estimation and entropy-based moment selection

In this paper, we make five contributions to the literature on information and entropy in generalized method of moments (GMM) estimation. First, we introduce the concept of the long run canonical correlations (LRCCs) between the true score vector and the moment function f(_vt,_θ0)$f(v_t,{\theta }_0)$ and show that they provide a metric for the information contained in the population moment condition E[f(_vt,_θ0)]=0$\mathrm{E}[f(v_t,{\theta }_0)]=0$. Second, we show that the entropy of the limiting distribution of the GMM estimator can be written in terms of these LRCCs. Third, motivated by the above results, we introduce an information criterion based on this entropy that can be used as a basis for moment selection. Fourth, we introduce the concept of nearly redundant moment conditions and use it to explore the connection between redundancy and weak identification. Fifth, we analyse the behaviour of the aforementioned entropy-based moment selection method in two scenarios of interest; these scenarios are: (i) nonlinear dynamic models where the parameter vector is identified by all the combinations of moment conditions considered; (ii) linear static models where the parameter vector may be weakly identified for some of the combinations considered. The first of these contributions rests on a generalized information equality that is proved in the paper, and may be of interest in its own right.     

环境规制对资源型城市转型非线性影响

为探究环境规制、资源型城市转型及其空间资源溢出间关系,从空间溢出视角出发,在2011—2021年的113个资源型地级市数据基础上,构建半参数门限空间杜宾模型(STSDM),探索了环境规制对资源型城市转型绩效的非线性关系及其非对称性空间溢出影响。结果表明：①线性假设下环境规制不利于城市转型绩效提升,但非线性假设下,环境规制在初期有利于资源型城市转型绩效提升,具备有“边际效应递减”的非线性长期特征,偏导图呈弱“U形”特征;②资源型城市转型绩效在空间资源溢出效应上存在有非对称性;③资源型城市环境规制处于越高阶段,能够获得城市绩效转型的空间资源溢出红利越少。据此提出要因地适宜设立环境规制政策、建立长效环境保护机制等政策性建议。     

Optimal adaptation strategies to face shocks on groundwater resources

We consider an exogenous and reversible shock to a groundwater resource, namely a decrease in the recharge rate of the aquifer. We compare optimal extraction paths and the social costs of optimal adaptation in two cases: under certainty, i.e. when the date of occurrence of the shock is known, and under uncertainty, when the date of occurrence of the shock is a random variable. We show that an increase in uncertainty leads to a decrease in precautionary behavior in the short run and to an increase in precautionary behavior in the long run. We apply our model to the particular case of the Western la Mancha aquifer in Spain. We show that, in this context, it is advantageous for the water agency to acquire information on the date of the shock, especially for high-intensity and intermediate-risk events.