HEDGING AND PORTFOLIO OPTIMIZATION UNDER TRANSACTION COSTS: A MARTINGALE APPROACH12

We derive a formula for the minimal initial wealth needed to hedge an arbitrary contingent claim in a continuous-time model with proportional transaction costs; the expression obtained can be interpreted as the supremum of expected discounted values of the claim, over all (pairs of) probability measures under which the “wealth process” is a supermartingale. Next, we prove the existence of an optimal solution to the portfolio optimization problem of maximizing utility from terminal wealth in the same model, we also characterize this solution via a transformation to a hedging problem: the optimal portfolio is the one that hedges the inverse of marginal utility evaluated at the shadow state-price density solving the corresponding dual problem, if such exists. We can then use the optimal shadow state-price density for pricing contingent claims in this market. the mathematical tools are those of continuous-time martingales, convex analysis, functional analysis, and duality theory.     

On the Existence of Minimax Martingale Measures

Embedding asset pricing in a utility maximization framework leads naturally to the concept of minimax martingale measures. We consider a market model where the price process is assumed to be an ^d‐semimartingale X and the set of trading strategies consists of all predictable, X‐integrable, ^d‐valued processes H for which the stochastic integral (H.X) is uniformly bounded from below. When the market is free of arbitrage, we show that a sufficient condition for the existence of the minimax measure is that the utility function u : → is concave and nondecreasing. We also show the equivalence between the no free lunch with vanishing risk condition, the existence of a separating measure, and a properly defined notion of viability.     

中国金融二元的产业解析

按照金融发展理论,收入结构影响储蓄结构,进而影响投资结构,最终定格于金融结构.中国城乡现有的金融结构格局是收入结构所决定的储蓄结构进而所形成的投资结构的结果,此结果可以从城乡产业发展水平即产业收益中求解.中国金融二元是产业二元演化的结果.     

From revealed preference to preference revelation

Utility functions are regarded as elements of a linear space that is paired with a dual representation of choices to demonstrate the similarity between preference revelation and the duality of prices and quantities in revealed preference. With respect to preference revelation, quasilinear versus ordinal utility and choices in an abstract set versus choices in a linear space are distinguished and their separate and common features are explored. The central thread uniting the various strands is the subdifferentiability of convex functions.     

Career, experience and returns to human capital: is the dual labour market hypothesis relevant for the UK?

This paper investigates the relationship between career status, labour market experience and returns to human capital accumulation in the context of a two-tier, career and non-career labour market. Using micro data from the British Household Panel Survey (BHPS), this study detects wage and employment mechanisms that differ between these two tiers of workers. The paper finds no support for the hypothesis of strict duality, by which the returns to education are expected to differ across labour market segments, with the returns in career employment being high and positive and the returns in the non-career sector being close to zero. The paper, however, finds support for significant returns to current tenure only in the career sector and also for the scarring hypothesis, according to which part-time employment and unemployment experience have a negative effect on participation and earnings in the career sector. Finally, there is evidence that only non-career earnings are significantly affected by local demand conditions, in contrast to earnings in the career sector. Career status is modelled as an endogenous variable subject to an initial job choice.     

基于马克思劳动价值论的逻辑辩证分析

马克思的劳动价值论,是一个完整的、科学的理论体系。它是揭示资本主义从起源到灭亡的基础理论,是建立科学社会主义的一个理论基石。马克思提出的价值理论包括劳动价值论和剩余价值论两部分,他认为"价值是凝结在商品中的无差别的人类劳动"。文章根据其主要内容,分析了马克思劳动价值论在科学社会主义学说中的逻辑线索和基础地位。     

马克思经济危机根源理论研究

坚持和发展马克思经济危机根源理论,可以从马克思生产关系两重性理论及其方法来认识马克思对经济危机根源的分析.马克思关于简单商品经济中就存在经济危机的可能性的分析,是从生产关系一般的角度阐明了经济危机根源于商品货币关系.马克思关于经济危机根源于资本主义基本矛盾的分析,既是从生产关系两重性关系的角度对商品经济的基本矛盾必然会和怎样会导致经济危机的进一步分析,也是从生产关系特殊的角度强调了社会基本经济制度对经济危机的重大影响.     

公司的领导权结构与经营绩效

公司的领导权结构反映了董事会的独立性和执行层创新自由的空间，它是公司内部治理结构的一个极其重要且高度可见的方面，依据来自中国证券市场数据的实证分析表明，领导权结构与公司绩效之间并不存在显著的线性关系，而且环境变量也未调和上述二者之间的联系。公司绩效的决定因素是很复杂的，而且是相互联系的，不能用单一的变量（如两职设置）来衡量，两职分设也并不是解决公司绩效问题的万能药。公司治理效率的根本决定因素在于合理的股权结构与市场化的人事任免机制。在现行的制度框架下，总经理兼任董事（不包括董事长）可能是一种较好的选择。     

The role of reference point in CEO restricted stock and its impact on R&D intensity in high‐technology firms

Prior work based on agency theory and behavioral agency model has focused on how absolute pay values affect firm outcomes. Departing from this traditional approach, we draw from behavioral decision theory to explain how relative pay levels influence firm risk taking. We investigate how CEO restricted stock value relative to reference point influences R&D intensity in high‐technology firms. We propose that negative deviation increases are related to R&D increases and positive deviation increases lead to R&D decreases, while negative deviation has greater effect than positive deviation. We establish theoretical boundary conditions by considering CEO duality and board vigilance as moderators. Drawing from agency theory, we predict the main effects will be enhanced under duality and weakened under high board vigilance. Our hypotheses are largely supported. Copyright © 2014 John Wiley & Sons, Ltd.     

Is an Outside Chair Always Better? The Role of Non‐CEO Inside Chairs on Corporate Boards

Proponents of separating the CEO and chairman positions advocate having an outside chairperson, although having an inside chairperson can be valuable for some firms. I find inside chairs are more likely where firm‐specific human capital is more important and, in these firms, inside chairs are associated with higher firm valuation and better operating performance. Furthermore, skilled inside chairs increase forced CEO turnover sensitivity to performance. The evidence suggests that certain inside chairs can be valuable when firm‐specific information is important for monitoring and an outside chair may be costly.