计量模型中的加总偏误与内生性：一种数值模拟方法

理论文献已经证明了细分数据模型的内生性和加总过程产生的内生性是加总偏误的根本原因。但是由于内生性涉及误差项与回归量之间的相关性问题,试图通过实证方法审视这两类内生性对加总偏误的影响变得比较困难,而数值模拟却是一个较为理想的方法。在数值模拟中,我们通过控制随机变量的分布形式以及随机变量之间的相关程度,进而对两类内生性因素产生的加总偏误进行全面细致的考察。本文的研究将为加总偏误的内生性解释提供有力证据。     

Community preferences and social choice

This paper gives necessary and sufficient conditions for the aggregation of preferences, extending an earlier treatment of aggregation by Stolper, Gorman, Samuelson and Chipman. Such aggregation procedures are intended to deal with the problem of aggregating demand functions in econometrics, where the aggregate is required to be independent to the income distribution. Thus, it is usually assumed in this form of aggregation that all consumers face the same prices, but that the distribution of income is unrestricted.In order to establish the characterisation result, we present a new approach to preference aggregation which involves summing certain subsets of the graphs of the preferences, viewed as subsets of a Euclidean space. This procedure has a clear geometrical interpretation, and a number of useful applications. In particular, it enables us to analyse the possibility of aggregation when prices are not constrained to be the same for all consumers, a case of possible empirical significance. We also show that the Stolper-Gorman-Samuelson-Chipman construction of community indifference curves coincides with a special case of this procedure.Finally, this approach allows us to develop the relationship between these forms of aggregation and the preference aggregation problem as it occurs in social choice theory.     

Group-based forecasting?: A social psychological analysis

The potential of group (vs. individual) forecasting is analyzed from the perspective of the social psychology of groups. The social decision scheme theory (SDST) is summarized, and several simulations are presented to demonstrate the dependence of group aggregation accuracy upon factors such as group size, the accuracy and distribution of individual forecasts, and shared representations of the forecasting problem. Many advantages and disadvantages of group aggregation are identified and related to four generic methods of group aggregation (statistical aggregation, prediction markets, the Delphi method, and face-to-face discussion). A number of aspects of forecasting problems are identified which should govern whether or not group forecasting can be relied upon, and if so, what aggregation method should be used.     

A formulation of the aggregation problem in terms of coalition and bargaining theory

The object of this paper is to demonstrate in economic terms the equivalence of the problem of aggregation in input-output analysis with coalition and bargaining problems. Depending on the specific norm for aggregation it is shown that the aggregation criterion and the coalition forming criterion in an n-person game leads to a broadly similar situation in the market sense given that the market operates to that criterion. It is also shown that a mathematical analogue to this formulation may be obtained via the techniques of geometric programming.     

Limiting Dictatorial rules

We consider the preference aggregation problem in infinite societies. In our model, there are arbitrarily many agents and alternatives, and admissible coalitions may be restricted to lie in an algebra. In this framework (which includes the standard one), we characterize, in terms of Strict Neutrality, the Ultrafilter Property of preference aggregation rules. Based on this property, we define the concept of Limiting Dictatorial rules, which are characterized by the existence of arbitrarily small decisive coalitions. We show that, in infinite societies which can be well approximated by finite ones, any Arrovian rule is limiting.     

Impact of an unexplained component of real exchange rate volatility on FDI: Evidence from transition countries

The aim of this paper is to examine the impact of an unexplained component of real exchange rate volatility on FDI in transition economies. We make an attempt to overcome some problems associated with previous studies; the aggregation problem, inadequate measures of volatility, short-run focus and the endogeneity problem. Using a GARCH specification, we focus on long-run volatility, while we control for the endogeneity problem by applying SYS-GMM estimation. The obtained results show that the impact of the unexplained component of real exchange rate volatility on FDI differs among economic activities since 2000. As part of the re-estimation exercise, we use two alternative measures of volatility to avoid arbitrariness. The obtained results are to a large extent in accordance with the first one.     

单井开发成本的模糊数综合评定方法

为了解决单井开发成本综合评议过程中多专家评议意见融合的问题,提出了一种基于模糊数的多专家评议意见融合方法,首先介绍了专家评议信息的模糊数表示方法以及专家评议信息之间的差异性测度的表示方法,最后给出了多专家意见的信息融合方法,最后利用数值算例论述了本方法的可行性。     

Some problems of data standardization

Procedure of aggregation of component indicators into one composite index of a multi-dimensional phenomenon under study requires previous standardization of the original raw data in terms of which the component indicators are expressed. The standardization is inevitably connected with an arbitrary choice of a mathematical formula by which the same measurement units, for all component indicators, are established. It is argued that by choosing one of the several possible standardization formulae, a researcher, most often unkowingly, ascribes differential weights to particular component indicators. Two approaches, in solving the problem of arbitrariness of the choice of the standardization formula, are possible: (1) assessment of the margin of “error of arbitrariness,” or “standardization effect,” and the interpretation of substantive results obtained after the aggregation, within that margin; (2) evaluation of equivalencies of things, established by the alternative standardization formulae, in order to choose the formulae ensuring the most acceptable equivalence as judged by certain objective norms or criteria. The two approaches are discussed, and numerical examples illustrating each of them are presented using two kinds of standardization: the one based on percentages, and the other on the deviation from the mean divided by standard deviation.     

基于粗糙集的建筑材料供应商选择方法

提出了一种基于粗糙集和模糊集理论相结合的方法,在信息熵知识的基础上,通过模糊聚类,客观的从实际数据中确定各评价准则的权重分配,从而综合评价供应商,为供应商管理提供数学依据。     

Smoothing demand by aggregation with respect to wealth

We suggest in this paper to treat the problem of smoothing demand by aggregation in a two-step procedure, corresponding to the two different constituents of consumption characteristics, wealth and preferences. Instead of imposing a manifold structure on preferences we exploit the nice structure of wealth-space. The first step of this procedure, aggregation with respect to wealth, is carried out. It is shown that, for any preference, aggregation with respect to wealth yields a mean demand which is almost everywhere C¹. Moreover, it is shown that for an important class of preferences, vanishing Gaussian curvature of indifference surfaces does not destroy differentiability of the mean demand function.     

Relative pricing of binary options in live soccer betting markets

Live soccer betting markets differ from other binary options markets in that all fundamental information is observable, the options mature in less than two hours and the markets are highly liquid. This study presents a new method for the identification of hidden information in market prices. The method is based on two independent Poisson distributions and on a numerical algorithm for the aggregation of all market price information into one rational number. The method is applied to an empirical dataset of real time market prices in 29,413 soccer games. The results indicate that the method selects the most profitable markets and allows for a significant improvement in average investment returns.     

Strategy-proof fuzzy aggregation rules

We investigate the structure of fuzzy aggregation rules which, for every permissible profile of fuzzy individual preferences, specify a fuzzy social preference. We show that all fuzzy aggregation rules which are strategy-proof and satisfy a minimal range condition are dictatorial. In other words, there is an individual whose fuzzy preferences determine the entire fuzzy social ranking at every profile in the domain of the aggregation rule. To prove this theorem, we show that all fuzzy aggregation rules which are strategy-proof and satisfy the minimal range condition must also satisfy counterparts of independence of irrelevant alternatives and the Pareto criterion. There has been hardly any treatment of the manipulability problem in the literature on social choice with fuzzy preferences.     

Aggregation in Input–Output Models: Prices and Quantities

This paper develops a joint theory of aggregation of input–output quantity and price models. The main emphasis is on the problem of aggregation of industries in the models. While aggregation of quantity models is a familiar topic in economic literature, the aggregation of price models is a largely unexplored subject. Here, however, quantity and price models are considered as two parts of a single, composite flow model. This understanding implies that each result in the quantity model has dual counterpart in the price model and vice versa. Through consistent use of this duality principle, significant results are developed for both model types, and a number of well-known results can be stated in a simpler way. Specifically, a number of conditions for perfect aggregation of final demands, primary inputs and industries in price models as well as quantity models are formulated. On this basis a new indicator of aggregation bias is suggested. The indicator can be decomposed into the contributions of each detailed industry, enabling the user to identify atypical industries in each group. Furthermore, the indicator can be computed even with no knowledge of the coefficients of the detailed models.     

TRUE VERSUS MEASURED THEIL INEQUALITY

This article deals with several problems that arise when the Theil coefficient of income inequality is computed in practice.
Aggregation of income data into brackets leads to an underestimation of the true Theil inequality, which is defined as the value of the coefficient as computed from individual income data. The assumption that the individual incomes are distributed according to a linear density function within the income brackets is suggested as a method to estimate this aggregation error. Calculations show that this method approximates the true aggregation error reasonably well.
Several methods are discussed concerning the treatment of negative incomes. In particular one can construct an income bracket that contains both negative and positive incomes and which in the summation formula is weighted with zero weight. Of all methods this procedure using the assumption of a linear density function within brackets, yields the highest value of the Theil coefficient and is thus preferred to the other alternatives.     

A new three-dimensional manufacturing service composition method under various structures using improved Flower Pollination Algorithm

With the growing complexity of customer requirements and the increasing scale of manufacturing services, how to select and combine the single services to meet the complex demand of the customer has become a growing concern. This paper presents a new manufacturing service composition method to solve the multi-objective optimization problem based on quality of service (QoS). The proposed model not only presents different methods for calculating the transportation time and transportation cost under various structures but also solves the three-dimensional composition optimization problem, including service aggregation, service selection, and service scheduling simultaneously. Further, an improved Flower Pollination Algorithm (IFPA) is proposed to solve the three-dimensional composition optimization problem using a matrix-based representation scheme. The mutation operator and crossover operator of the Differential Evolution (DE) algorithm are also used to extend the basic Flower Pollination Algorithm (FPA) to improve its performance. Compared to Genetic Algorithm, DE, and basic FPA, the experimental results confirm that the proposed method demonstrates superior performance than other meta heuristic algorithms and can obtain better manufacturing service composition solutions.     

直觉梯形模糊几何集成算子及其在群决策中的应用

文章首先定义了直觉梯形模糊数及其运算法则,基于这些运算法则,给出了直觉梯形模糊几何集成算子,即直觉梯形模糊加权几何(IT-WG)算子、直觉梯形模糊有序加权几何(IT-OWG)算子以及直觉梯形模糊混合几何(IT-HG)算子。在此基础上,提出了在属性权重已知的情形下专家评价值以直觉梯形模糊信息给出的多属性群决策方法。最后以产品最优设计方案的选择为实例进行分析,所得结果验证了该方法的有效性。     

A simple and effective scanning rule for a multi-channel system

We consider a multi-channel system in which one apparatus makes a sequence of observations, one at a time. By means of scanning, i.e. selecting a channel to be analyzed at any instant and deciding to stop at some stage, it is required to determine the channel in which there is the signal with prescribed constraints on error probabilities. A simple scanning rule, based on a cyclic application of a sequential probability ratio test (SPRT) is proposed for this problem. It is proved that in the case of Brownian motion, the expected scanning time of this rule is equal to the one of the optimal scanning rule (which is known only for this case). The simple structure of this rule permits to obtain corrected Brownian approximations for its characteristics in the case of exponential family of distributions. The same procedure is used in multi-channel change point problem.     

Simple aggregation and disaggregation subject to minimal information loss and other criteria

The main purpose of this paper is to develop a method and an algorithm for the aggregation as well as disaggregation of n-way tables, thereby minimizing a set of suitable criteria. One should observe that there is no real difference between aggregation and disaggregation when using this method. Here are presented some basic facts about a mainly one-dimensional method and an outline showing how the method may be extended to more complex cases.     

The mystification of operational competitiveness rating analysis

This note examines the fault of the operational competitiveness rating analysis (OCRA) method. The premise of the OCRA method requires that a single scalar measurement must be applied to inputs and outputs to calculate the performance ratings for production units. This property renders the OCRA method worthless, since simple comparisons of the aggregated inputs and outputs can generate accurate productive efficiency evaluation results for production units if the simple aggregation can be done. To avoid this problem, the OCRA method includes subjective weighting elements for input and output categories, so called calibration constants, into the performance rating computation. This approach of the OCRA method introduces much confusion for productive efficiency evaluation, and it violates the economics axiom of output/input maximization in its application context. Copyright © 2005 John Wiley & Sons, Ltd.     

An empirical analysis of linear aggregation problems: The case of investment behavior in Japanese firms

Some economists have analysed empirically linear aggregation problems from various view-points and get results which seem to justify the use of aggregated data. However, some were based on only one experiment. Using more experiments we shall analyse empirically two important aggregation problems for the case of the investment behavior of firms. In contrast to earlier studies, our results indicate that the aggregation biases of macroparameters are rather large and the explanatory power of the macroequations is not necessarily higher than that of a sum of microequations.