Basket trading under co-integration with the logistic mixture autoregressive model

In this paper, we propose a co-integration model with a logistic mixture auto-regressive equilibrium error (co-integrated LMAR), in which the equilibrium relationship among cumulative returns of different financial assets is modelled by a logistic mixture autoregressive time series model. The traditional autoregression (AR) based unit root test (ADF test), used in testing co-integration, cannot give a sound explanation when a time series passes the ADF test. However, its largest root in the AR polynomial is extremely close to, but less than, one, which is most likely the result of a mixture of random-walk and mean-reverting processes in the time series data. With this background, we put an LMAR model into the co-integration framework to identify baskets that have a large spread but are still well co-integrated. A sufficient condition for the stationarity of the LMAR model is given and proved using a Markovian approach. A two-step estimating procedure, combining least-squares estimation and the Expectation-Maximization (EM) algorithm, is given. The Bayesian information criterion (BIC) is used in model selection. The co-integrated LMAR model is applied to basket trading, which is a widely used tool for arbitrage. We use simulation to assess the model in basket trading strategies with the statistical arbitrage feature in equity markets. Data from several sectors of the Hong Kong Hang Seng Index are used in a simulation study on basket trading. Empirical results show that a portfolio using the co-integrated LMAR model has a higher return than portfolios selected by traditional methods. Although the volatility in the return increases, the Sharpe ratio also increases in most cases. This risk–return profile can be explained by the shorter converging period in the co-integrated LMAR model and the larger volatility in the ‘mean-reverting’ regime.     

中国农村经济市场化指数——各地区的相对进程研究

农村是中国经济体制改革的起点,农村经济市场化是中国经济市场化的重要组成部分。中国市场化进程的不平衡性不仅体现在城乡之间,也体现在农村内部。从市场化的基本含义和基本要求出发,科学地设计农村经济市场化的各项指标并对之进行测算,进而了解各地农村经济的市场化相对进程和各经济指标之间相互关系对于建设社会主义新农村具有重要意义。     

Should public policy respond to positional externalities?

A nice suit is one that compares favorably with those worn by others in the same local environment. More generally, a positional good is one whose utility depends strongly on how it compares with others in the same category.¹A positional externality occurs when new purchases alter the relevant context within which an existing positional good is evaluated.² For example, if some job candidates begin wearing expensive custom-tailored suits, a side effect of their action is that other candidates become less likely to make favorable impressions on interviewers. From any individual job seeker's point of view, the best response might be to match the higher expenditures of others, lest her chances of landing the job fall. But this outcome may be inefficient, since when all spend more, each candidate's probability of success remains unchanged. All may agree that some form of collective restraint on expenditure would be useful.In such cases, however, it is often impractical to negotiate private solutions. Do positional externalities then become legitimate objects of public policy concern? In attempting to answer this question, I employ the classical libertarian criterion put forth by John Stuart Mill³, who wrote the state may not legitimately constrain any citizen's freedom of action except to prevent harm to others. I argue that many positional externalities appear to meet Mill's test, causing not just negative feelings but also large and tangible economic costs to others who are ill-equipped to avoid them. I also discuss an unintrusive policy remedy for positional externalities, one modeled after the use of effluent charges to curb environmental pollution.The paper is organized as follows. Section 1 notes the deep similarity between the conditions that give rise to positional arms races and those that give rise to conventional military arms races. Section 2 follows with a review of evidence concerning the strength of concerns about relative position. Section 3 describes some of the tangible economic costs that people experience as a result of positional externalities arising from such concerns. Section 4 takes up the question of whether collective action directed against positional externalities is consistent with respect for individual rights. Section 5 describes how a progressive consumption tax could neutralize many of the most costly effects of positional externalities.     

我国省对县(市)一般性转移支付的绩效评价——基于DEA二次相对效益模型的研究

一般性转移支付是我国转移支付制度的重要组成部分,它是中央财政为了平衡地区间财力差异、促进基本公共服务均等化为目的的重要制度安排。然而,中央财政以均等化为目标、以标准财政收支差为依据对省(市、自治区)拨付一般性转移支付资金,以及省对县(市)级政府拨付该项资金时,并没有规定具体用途,因此,县(市)级地方政府拥有对这部分资金完全的自主支配权。在多重目标,尤其是经济增长目标的压力下,一般性转移支付资金可能被挪用和挤占,上级政府实现公共服务均等化的政策意图难以达到预期的效果。本文的目的是:从制度层面论述一般性转移支付政策目标与效率评价的内在联系;探讨DEA二次相对效益模型对一般性转移支付绩效评价的适用性;从基本公共服务资金配置和提升效率两个方面,构建了省对县(市)一般性转移支付绩效评价体系;以云南省的县(市)为样本,对一般性转移支付绩效进行实证模拟评价;提出建立绩效评价是完善省对县(市)一般性转移支付制度的重要内容。     

Migration and its Determinants: A Study of Two Communities in Colombia

Using data gathered by the author in two communities in Southwestern Colombia, this paper tests a model of migration which incorporates relative deprivation as one of many possible reasons to migrate. The study finds that the product of relative deprivation and family income not only has a sensible interpretation; it is a better predictor of migration than its two component variables alone. Results also show that families with the highest propensities to migrate are those with the most to gain in terms of being better able to reduce relative deprivation through successful migration. These families, however, are neither at the bottom nor at the top of the income distribution in their communities. The study also finds that those most likely to migrate to the USA conform most closely to the immigration policies of the USA.

社会资本在减轻农村贫困中的作用：文献述评与研究展望

近年来,社会资本在减轻农村贫困中的作用逐渐成为发展经济学家关注的一个热点。本文分别从静态和动态两个视角综述了相关研究的思路和方法：从静态视角来看,信任对于减少绝对贫困有积极的作用,但某些形式的社会资本难以减轻绝对贫困,关于社会资本是否能减轻相对贫困则尚未取得一致的认识;从动态视角来看,社会资本通过非正式保险的机制平滑消费、减轻暂时贫困,通过促进融资和创业、保护产权、促进公共品提供和劳动力流动,有助于消除长期贫困。总的来看,随着市场化进程的深入,社会资本反贫困的积极作用有减弱的趋势。本文基于理论评述,提出了深化社会资本的减贫理论机制（尤其是对相对贫困的作用机制）、市场化进程中的社会资本反贫困机制、改进社会资本测量、加强因果效应识别等未来的研究方向。     

中国海洋产业灰色关联及发展前景分析

本文根据中国海洋统计年鉴和国家海洋局公布的中国海洋经济统计公报提供的数据资料,利用灰色关联分析原理与方法对中国海洋产业发展进行了关联度分析,并在此基础上分析了海洋产业发展前景与趋势。     

国际贸易对我国行业间收入分配的影响——基于制造业面板数据的实证分析

本文运用我国1998-2006年27个制造业行业的面板数据对国际贸易的行业间收入分配效应进行了实证研究。研究发现,从总体上看,出口对行业相对工资有正向的上拉作用,进口对行业相对工资有负向的下拉作用。但进出口对不同类型行业的影响程度和方向不同,出口贸易对资本密集型和劳动密集型制造业行业的相对工资均有上拉作用,且对前者的促进作用大于后者;进口贸易对劳动密集型制造业行业的相对工资有下拉作用,而对资本密集型制造业行业的相对工资有上拉作用。基于上述结论,促进出口,提高劳动密集型产品的附加值,适当控制最终消费品等产品的进口,有助于缩小行业收入差距。     

Relative entropy in sequential decision problems

Consider an agent who faces a sequential decision problem. At each stage the agent takes an action and observes a stochastic outcome (e.g., daily prices, weather conditions, opponents' actions in a repeated game, etc.). The agent's stage-utility depends on his action, the observed outcome and on previous outcomes. We assume the agent is Bayesian and is endowed with a subjective belief over the distribution of outcomes. The agent's initial belief is typically inaccurate. Therefore, his subjectively optimal strategy is initially suboptimal. As time passes information about the true dynamics is accumulated and, depending on the compatibility of the belief with respect to the truth, the agent may eventually learn to optimize. We introduce the notion of relative entropy, which is a natural adaptation of the entropy of a stochastic process to the subjective set-up. We present conditions, expressed in terms of relative entropy, that determine whether the agent will eventually learn to optimize. It is shown that low entropy yields asymptotic optimal behavior. In addition, we present a notion of pointwise merging and link it with relative entropy.     

充分发挥比较优势 加快发展县域经济——对云南省大理州县域经济发展的思考

发展县域经济在边疆民族地区全面建设小康社会的战略中占有极为重要的地位。加快发展县域经济，必须顺应经济社会发展的趋势，以市场为导向、资源为依托、效益为核心，立足于充分发挥比较优势，积极构建特色产业和优势产业，确立科学的发展思路和重点，采取有力措施，加快资源优势向产业优势和经济优势转化，促进县域经济的可持续发展和全面建设小康社会目标的早日实现。