A Review on Dimension Reduction

Summarizing the effect of many covariates through a few linear combinations is an effective way of reducing covariate dimension and is the backbone of (sufficient) dimension reduction. Because the replacement of high‐dimensional covariates by low‐dimensional linear combinations is performed with a minimum assumption on the specific regression form, it enjoys attractive advantages as well as encounters unique challenges in comparison with the variable selection approach. We review the current literature of dimension reduction with an emphasis on the two most popular models, where the dimension reduction affects the conditional distribution and the conditional mean, respectively. We discuss various estimation and inference procedures in different levels of detail, with the intention of focusing on their underneath idea instead of technicalities. We also discuss some unsolved problems in this area for potential future research.     

Inflation, Price Level and Hybrid Rules under Inflation Uncertainty

The performance and robustness of optimised interest rate rules are analysed in a New Keynesian model estimated for the euro area economy. In particular, we examine the properties of rules responding to inflation, the price level, or a combination of the two (a hybrid rule). All the rules also respond to the output gap. The optimal hybrid rule is only marginally superior when there is no model uncertainty. When there is uncertainty about the degree of inflation persistence, the inflation rule is the most robust rule and the performance of the other two rules deteriorates. However, all the rules perform well if the true degree of inflation persistence turns out to be less than policymakers’ estimate.     

ELECTRE TRI for Groups with Imprecise Information on Parameter Values

ELECTRE TRI is a well-known method to assign actions to predefined ordered categories, considering multiple criteria. Using this method requires setting many parameters, which is often a difficult task. We consider the case where a group of Decision Makers (DMs) is unsure of which values each parameter should take, which may result from insufficient, imprecise or contradictory information, as well as from lack of consensus among the group members. In a framework where DMs provide constraints bounding and interrelating the parameter values, rather than fixing precise figures, we discuss the problem of finding the best and worst category that each action may attain.     

COHERENT ACCEPTABILITY MEASURES IN MULTIPERIOD MODELS

The framework of coherent risk measures has been introduced by Artzner et al. (1999; Math. Finance 9, 203–228) in a single-period setting. Here, we investigate a similar framework in a multiperiod context. We add an axiom of dynamic consistency to the standard coherence axioms, and obtain a representation theorem in terms of collections of multiperiod probability measures that satisfy a certain product property. This theorem is similar to results obtained by Epstein and Schneider (2003; J. Econ. Theor. 113, 1–31) and Wang (2003; J. Econ. Theor. 108, 286–321) in a different axiomatic framework. We then apply our representation result to the pricing of derivatives in incomplete markets, extending results by Carr, Geman, and Madan (2001; J. Financial Econ. 32, 131–167) to the multiperiod case. We present recursive formulas for the computation of price bounds and corresponding optimal hedges. When no shortselling constraints are present, we obtain a recursive formula for price bounds in terms of martingale measures.     

An exercise in composite indicators construction: Assessing the sustainability of Italian regions

This paper presents a piece of research aimed at evaluating the relative sustainability of the Italian Regions. After selecting a core set of indicators, for which we referred to the EU Sustainable Development Strategy, we built a composite index and checked for its robustness. As a result we got ‘many numbers’, that is, a range of possible rankings for Italian Regions.     

一种改进基于瞬时无功功率的谐波电流检测方法

我国电力系统大多数处在不平衡状态下，文章对现有的基于瞬时无功功率谐波的检测方法进行改进，并采用瞬时无功功率闭环检测，使检测系统鲁棒性强、稳定度好。仿真结果验证了该方法的实用性及可行性。     

Regression Sampling in Statistical Auditing: A Practical Survey and Evaluation

Several confidence intervals for the regression estimator are surveyed. A Monte Carlo experiment, based on the NETER and LOEBBECKE (1975) populations, gives estimated coverages and lengths of the different confidence intervals. One interval is exact under the assumption of multivariate normal distributions; it gives longer intervals (hence better coverages) than the interval based on a popular variance estimator. An interval due to ROBERTS (1970) is much too long. Jackknifing gives robust intervals. Rules of thumb for practitioners are given.     

Does Tourism Promote Cross-Border Trade?

We estimate a simultaneous bivariate qualitative choice model of Arizona agribusiness firms' propensity to trade and visit as a tourist the cross-border state of Sonora, Mexico. Venture business visits, quantified through the tourism equation, were found to have the largest impact on a firm's propensity to trade. Tourist visits have a greater impact on trade when combined with other firm attributes such as age, perceived need for geographic diversity, foreign language fluency, and firm size, than if considered alone. Our results suggest that there is a role for government agencies to play in overcoming imperfect information related to trade opportunities through facilitating exploratory business venture and tourist visits.     

财政分权与城乡居民收入差距

采用动态面板方法,利用我国2003-2012年的省级面板数据对财政分权与城乡居民收入差距之间的关系进行了深入研究.结果发现：财政分权对缩小我国城乡居民收入差距具有显著的促进作用,这种促进作用在区域间有所差异.财政分权对缩小东中部地区城乡差距的作用程度相当,对缩小西部城乡居民收入差距作用略小.在全国范围内,农村地区人力资本水平与城乡居民收入差距呈负相关,农村地区人力资本越高,越容易缩小城乡居民收入差距.     

供应链网络的鲁棒性探微

供应链网络具有复杂性、动态性、开放性和网络型的特征。由于内部不确定性和外部不确定性的存在,供应链存在相当风险。为了减轻风险企业和供应链越来越倾向运用鲁棒性的方法来经营企业和供应链。供应链鲁棒性管理主要分为鲁棒供应管理、需求管理、产品管理和信息管理。供应链鲁棒性运作管理在解决供应链不稳定问题中发挥了至关重要的作用,使供应链网络不确定性问题得到解决,也使供应链网络中的企业能够优势互补、规避风险,使企业能够协同实现产业内的合作与发展。