CATEGORISATION OF ADDITIVE PURCHASING POWER PARITIES

Additivity is an important property for the aggregation methods used in constructing purchasing power parities. For a practical definition of additivity, this paper categorises all aditive methods. First of all, a generalisation of the Geary-Khamis method of aggregation is defined: this is called the Generalised Geary-Khamis, (GGK), approach. The key result proved is that, within a broad class of possible aggregation methods, the set of additive methods is precisely equivalent to the set of GGK indices. Some implications of this categorisation of additive methods are considered, both in the multilateral and bilateral cases. For example, in the multilateral case, the Iklé index is set in context as another special case of the GGK approach. In the bilateral case, it is shown that there always exists a GGK, (and therefore additive), equivalent to the Fisher Index.     

Asset price bubbles in Arrow-Debreu and sequential equilibrium

Summary. Price bubbles in an Arrow-Debreu equilibrium in an infinite-time economy are a manifestation of lack of countable additivity of valuation of assets. In contrast, the known examples of price bubbles in a sequential equilibrium in infinite time cannot be attributed to the lack of countable additivity of valuation. In this paper we develop a theory of valuation of assets in sequential markets (with no uncertainty) and study the nature of price bubbles in light of this theory. We define a payoff pricing operator that maps a sequence of payoffs to the minimum cost of an asset holding strategy that generates it. We show that the payoff pricing functional is linear and countably additive on the set of positive payoffs if and only if there is no Ponzi scheme, provided that there is no restriction on long positions in the assets. In the known examples of equilibrium price bubbles in sequential markets valuation is linear and countably additive. The presence of a price bubble means that the dividends of an asset can be purchased in sequential markets at a cost lower than the asset's price. We present further examples of equilibrium price bubbles in which valuation is nonlinear, or linear but not countably additive.     

技术选择、技术扩散与经济收敛

Lin(1994,1996a,b,1999,2001)的技术选择假说认为一个国家的经济结构是由其要素禀赋结构内生决定的.一个发展中国家政府所采取的发展战略如背离了最优的技术选择将影响该国的经济增长速度及是否能够向发达国家的收入水平收敛.本文构建了一个增长函数,除技术选择外,还同时考虑地理位置、政府质量等因素在长期内对各国全要素生产率(TFP)的影响.我们用跨国数据对该模型进行估计,检验影响长期TFP差异的各种假说,结果支持Lin的技术选择假说、Sachs et al.(1995,1999)的地理位置假说,但结果未支持政府质量假说.     

基于后悔规避的投资组合模型及其实证分析

由于人的情感、认知等因素对投资活动有直接影响,本文在投资活动中引入人的情感因素,提出了基于后悔规避的投资者效用函数,该效用函数是期末财富和预期财富的函数。建立了存在无风险资产时的最优投资组合模型,发现基于后悔规避投资组合模型的组合前沿存在两基金分离的现象。对我国上海股票市场进行了实证分析,得到了基于后悔规避投资组合模型的组合前沿,并验证了组合前沿存在两基金分离现象的结论。     

Discrete Choice with Social Interactions

This paper provides an analysis of aggregate behavioural outcomes when individual utility exhibits social interaction effects. We study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behaviour of others in an environment of noncooperative decisionmaking. Laws of large numbers are generated in such environments. Multiplicity of equilibria in these models, which are equivalent to the existence of multiple self-consistent means for average choice behaviour, will exist when the social interactions exceed a particular threshold. Local stability of these multiple equilibria is also studied. The properties of the noncooperative economy are contrasted with the properties of an economy in which a social planner determines the set of individual choices. Finally, a likelihood function based on the theoretical model is given and conditions for the econometric identifiability of the model are established.     

School Choice and the Intergenerational Poverty Trap

This paper formulates a dynamic altruistic model of parental choice of school quality and intergenerational social mobility. It shows that when there are many school qualities, the earnings of children as a function of parental schooling investment is a non‐concave function, which leads to multiple steady‐state equilibria. The paper studies the intergenerational dynamics of parental schooling investment and gives conditions on the rate of return from parental schooling investment under which some families are stuck in an intergenerational poverty trap. The policy implications are also discussed.     

Choice and individual welfare

We propose an abstract method of systematically assigning a “rational” ranking to non-rationalizable choice data. Our main idea is that any method of ascribing welfare to an individual as a function of choice is subjective, and depends on the economist undertaking the analysis. We provide a simple example of the type of exercise we propose. Namely, we define an individual welfare functional as a mapping from stochastic choice functions into weak orders. A stochastic choice function (or choice distribution) gives the empirical frequency of choices for any possible opportunity set (framing factors may also be incorporated into the model). We require that for any two alternatives x and y, if our individual welfare functional recommends x over y given two distinct choice distributions, then it also recommends x over y for any mixture of the two choice distributions. Together with some mild technical requirements, such an individual welfare functional must weight every opportunity set and assign a utility to each alternative x which is the sum across all opportunity sets of the weighted probability of x being chosen from the set. It therefore requires us to have a “prior view” about how important or representative a choice of x at a given situation is.     

Strategy-Proofness and the Tops-Only Property

A social choice function satisfies the tops‐only property if the chosen alternative only depends on each person's report of his most‐preferred alternatives on the range of this function. On many domains, strategy‐proofness implies the tops‐only property provided that the range of the social choice function satisfies some regularity condition. The existing proofs of this result are model specific. In this paper, a general proof strategy is proposed for showing that a strategy‐proof social choice function satisfies the tops‐only property when everyone has the same set of admissible preferences.     

Decomposable Strategy-Proof Social Choice Functions

This article shows that a social choice function defined on a domain of separable preferences which satisfies a relatively weak domain-richness condition on a product set of alternatives is (i) strategy-proof and only depends on the tops of the individual preferences if and only if (ii) the range of the social choice function is a product set and the social choice function can be decomposed into the product of one-dimensional, strategy-proof, nontop-insensitive social choice functions.
JEL Classification Number: D71.     

基于离散选择模型的顾客选择偏好分析

准确把掌握细分市场上消费者的需求和选择偏好是企业获取较好市场回报的关键.本文以访谈和调查问卷的数据信息为基础,针对消费者个体特征方面的多个因素变量,运用离散选择模型,研究对液态奶制品的某个特征因素作为首选因素的影响分析.同时,针对消费者某一特征因素对液态奶的多个特征因素的选择偏好的影响,给出了基于Logit模型和SPSS软件的统计分析和合理解释.通过对液体奶制品消费者的个体特征和选择液态奶的某一特定因素为首选因素的关系分析,以及顾客选择偏好方面的探讨,为我国液态奶制品供应链在目标市场的选择方面提供了一些启示.     

就业再选择与劳动力市场效率

本文认为就业再选择是劳动力市场的基本特征。通过就业再选择使企业内部劳动力市场与外部劳动力市场连接在一起而成为一个整体。劳动者进行就业再选择的频度和难易程度,决定企业内外劳动力市场一体化的程度和劳动力市场的效率水平。因此,企业的人力资源管理,则必须摆脱“员工属于组织”的传统观念,以员工的就业再选择为出发点,并且,促进劳动者进行就业再选择才是建立健全劳动力市场机制的根本途径。     

Freedom of Choice and Poverty Alleviation

The Capability Approach (henceforth CA) views poverty as a multidimensional phenomenon that is not only characterised by lows levels of achievement in the various dimensions but also by a restricted opportunity to choose among different ways of life. The CA thus puts a lot of emphasis on (limited) freedom of choice as a crucial aspect of poverty. If poverty is seen in this way there are two ways to improve the situation of the poor: by broadening the set of opportunities open to them or by strengthening their ability to choose. The paper concentrates on the latter. Although the CA discusses several possibilities for strengthening the ability to choose it does not explicitly consider the role of enhancing the capability of choosing as a means of poverty alleviation. The paper summarizes which circumstances are seen in the CA as suitable for strengthening freedom of choice. Namely, the paper discusses the market as an institution that trains the ability to choose, democracy as a political institution that is based on freedom of choice and participatory methods as an attempt to build explicitly on freedom of choice of the participants. Two shortcomings in the theoretical conceptualization of freedom of choice in the CA are identified by discussing these institutions and circumstances: first, the interplay between social structures and individual agency is not modelled in much detail within the CA. Second, the CA does not provide an explicitly temporal model of agency. The paper takes a closer look at these shortcomings from a sociological perspective since the questions they raise are core questions of sociology. The problems are intertwined. In order to tackle the problem of social embedding in the CA one needs to introduce time and processes as well. Sociological approaches show how social structures evolve from the interaction of individuals. The paper gives an example of how sociological concepts of this interaction can be used for drawing a model of social work for strengthening the agency of the poor. The paper proceeds as follows: first the view of poverty as capability deprivation is presented. The second section gives an overview of the areas in which the CA discusses the strengthening of individual choice: the market, democracy and participatory projects. The third section elaborates on the shortcomings of the CA identified in the preceding section from a sociological perspective and introduces a concept of social work developed in a similar theoretical context. The conclusion summarizes the lessons and outlines further lines of research.     

Ronald Coase's Method of Building More Realistic Models of Choice

This paper argues that Ronald Coase's major contributions to economic theory are best understood in terms of the distinct method he used to build more realistic models of choice. We call his method the benchmark-comparison method. It consists of building models of choice and then using them as benchmarks in the further investigation of economic interaction, either by comparing the benchmark models with observed interaction or by building additional models of choice, which may themselves function as benchmarks. The paper first describes the method then demonstrates how Coase used it in his two most famous papers. We go on to show how an understanding of the method confirms Coase's own statements about the continuity of his thought. Finally, we assess Coase's critique of Milton Friedman's positivist methodology and discuss a recent paper on Coase's methodology.     

流动性、生命周期与投资组合相异性——中国投资者行为调查实证分析

本文采用Probit和Tobit模型对中国居民的股票市场参与和投资组合的影响因素进行了分析,主要有以下的实证发现:首先,不流动性资产特别是房地产的投资显著影响了投资者的股票市场参与和投资组合,而且影响以“替代”效应或者说“挤出”效应为主。其次,投资者在进行投资组合时极少利用股票市场对其未来现金流所承担的风险进行对冲,也就是说,中国居民投资的“生命周期效应”不明显;第三,中国居民投资的“财富效应”非常显著。财富的增加既增加了居民参与股票市场的概率,也增加了居民参与股票市场的深度。     

Robust Implementation in Direct Mechanisms

A social choice function is robustly implementable if there is a mechanism under which the process of iteratively eliminating strictly dominated messages lead to outcomes that agree with the social choice function for all beliefs at every type profile. In an interdependent-value environment with single-crossing preferences, we identify a contraction property on the preferences which together with strict ex post incentive compatibility is sufficient to guarantee robust implementation in the direct mechanism. Strict ex post incentive compatibility and the contraction property are also necessary for robust implementation in any mechanism, including indirect ones. The contraction property requires that the interdependence is not too high. In a linear signal model, the contraction property is equivalent to an interdependence matrix having all eigenvalues smaller than one.     

Additivity in bankruptcy problems and in allocation problems

We study the property of additivity in bankruptcy problems and in allocation problems. In bankruptcy problems we use this property to characterize the Talmudic rule proposed by Rabbi Ibn Ezra. Moreover we generalize this rule to every bankruptcy problem. Again, using additivity we characterize the rights egalitarian solution in allocation problems.     

消费者选择理论的重构——品牌与数量选择的两步法经济分析

传统经济学中的消费者选择理论中的效用函数只考虑了商品数量对效用的影响，而在品牌时代，随着可供选择的多样化，消费者在选择数量之前必然首先对品牌做出选择。因此可分两步来构建消费者选择理论：第一步是研究品牌与选择行为，消费者依据约束条件下选择成本最小化原则进行品牌选择；第二步是数量与选择行为，消费者依据约束条件下的效用最大化原则进行数量选择。将这两方面结合起来，可以重新构建品牌时代较为完整的消费者选择理论。     

中国电信业的制度变迁及其路径选择

本文用新制度经济学的制度变迁理论研究了中国电信产业的制度变迁的必然性。从制度需求和制度供给的变化探讨电信制度变迁的必要性和可能性,认为技术变革、市场需求、相对价格变化以及其它制度的变化导致了制度需求的变化,而制度环境变迁、社科知识的进步以及对其它制度的吸收借鉴引起了制度供给的变化。在审视已有的制度变迁的现状的同时,本文提出营造有效的市场竞争环境、产权制度改革以及产业管制重建是今后中国电信业制度变迁的路径选择。     

A note on the optimal choice of monetary and fiscal policy

This paper studies the instrument-target problem associated with a simple macroeconomic model with conditions of uncertainty. The purpose of the paper is to demonstrate that if a model is linear with nonstochastic coefficients and with additive disturbances and if the policy objective is to maximize the expected value of the quadratic loss function, then it is the choice of endogenous variables that alters the expected loss value. This contrasts with the findings of Poole, Sargent, Turnovsky, et al., in which the expected losses are compared for different instruments while endogenous variables are changed at the same time. Thus, if basic model specifications are unchanged, an important cause for different expected losses under different policy instruments is seen to lie in the choice of endogenous variables.     

The Interpretation of Instrumental Variables Estimators in Simultaneous Equations Models with an Application to the Demand for Fish

In markets where prices are determined by the intersection of supply and demand curves, standard identification results require the presence of instruments that shift one curve but not the other. These results are typically presented in the context of linear models with fixed coefficients and additive residuals. The first contribution of this paper is an investigation of the consequences of relaxing both the linearity and the additivity assumption for the interpretation of linear instrumental variables estimators. Without these assumptions, the standard linear instrumental variables estimator identifies a weighted average of the derivative of the behavioural relationship of interest. A second contribution is the formulation of critical identifying assumptions in terms of demand and supply at different prices and instruments, rather than in terms of functional-form specific residuals. Our approach to the simultaneous equations problem and the average-derivative interpretation of instrumental variables estimates is illustrated by estimating the demand for fresh whiting at the Fulton fish market. Strong and credible instruments for identification of this demand function are available in the form of weather conditions at sea.