中国股市大公司与小公司股票动态价格关系研究——以钢铁行业为例

从中国上海和深圳股票市场选择了钢铁股票22家,根据差别信息集理论,探究了该行业内股票价格的长期协动关系以及收益的领先—滞后关系,发现钢铁大公司股票与其小公司股票价格的长期协动关系仅存在于牛市阶段.在熊市阶段,大公司股票的收益对小公司股票收益存在信息领先趋势.并给出了实际操作建议.     

A Practical Approach for Determining Rectangular Stock Sizes

In this paper we address the problem of determining what rectangular sizes should be stocked in order to satisfy a bill of materials composed of smaller rectangles. As is common in many manufacturing operations, the stock material will be cut using two-staged guillotine cutting patterns. We first generate a large number of stock sizes ideally suited to the bill of materials. Then we use a facility location algorithm to consolidate the stock sizes down to an acceptable number. Given the solution of what rectangular sizes to stock, a second program is used to map bills of materials into the stock rectangles. The effectiveness of our approach is demonstrated by generating stock sizes for a real-world bill of materials with 392 distinct order sizes and over 7700 order pieces.     

A multi-objective programming approach to 1.5-dimensional assortment problem

In this paper we study a 1.5-dimensional cutting stock and assortment problem which includes determination of the number of different widths of roll stocks to be maintained as inventory and determination of how these roll stocks should be cut by choosing the optimal cutting pattern combinations. We propose a new multi-objective mixed integer linear programming (MILP) model in the form of simultaneously minimization two contradicting objectives related to the trim loss cost and the combined inventory cost in order to fulfill a given set of cutting orders. An equivalent nonlinear version and a particular case related to the situation when a producer is interested in choosing only a few number of types among all possible roll sizes, have also been considered. A new method called the conic scalarization is proposed for scalarizing non-convex multi-objective problems and several experimental tests are reported in order to demonstrate the validity of the developed modeling and solving approaches.     

Mixed-integer programming approaches for index tracking and enhanced indexation

We consider the problem of reproducing the performance of a stock market index, but without purchasing all of the stocks that make up the index, index tracking. We also consider the problem of out-performing the index, enhanced indexation. We present mixed-integer linear programming formulations of these problems. Our formulations include transaction costs, a constraint limiting the number of stocks that can be purchased and a limit on the total transaction cost that can be incurred. As our formulations of these problems are mixed-integer linear programs we can use a standard solver (Cplex). Numeric results are presented for eight data sets drawn from major markets. The largest of these data sets involves over 2000 stocks.     

中国证券市场价值溢价实证研究

以1995年7月—2005年12月我国证券市场深沪两市的上市公司为样本,考察了价值溢价随规模变化的规律,并检验了CAPM能否解释价值溢价以及与权益帐面市值比B/M(或规模)无关的贝塔(β)能否与股票的平均收益相补偿.实证检验发现:1)中国股市存在一定程度的价值溢价,尤其是小规模(S ize)价值股在平均收益上存在着明显的价值溢价,而大规模(S ize)价值股则不存在价值溢价现象.2)CAPM能够解释我国股市从1995年7月至2005年12月期间的价值溢价.     

Periodic control of intermittent demand items: theory and empirical analysis

In this paper we propose a modification to the standard forecasting, periodic order-up-to-level inventory control approach to dealing with intermittent demand items, when the lead-time length is shorter than the average inter-demand interval. In particular, we develop an approach that relies upon the employment of separate estimates of the inter-demand intervals and demand sizes, when demand occurs, directly for stock control purposes rather than first estimating mean demand and then feeding the results in the stock control procedure. The empirical performance of our approach is assessed by means of analysis on a large demand data set from the Royal Air Force (RAF, UK). Our work allows insights to be gained on the interactions between forecasting and stock control as well as on demand categorization-related issues for forecasting and inventory management purposes.     

MIXED-STOCK VS. TERMINAL FISHERIES: A BIOECONOMIC MODEL

ABSTRACT. This paper develops a bioeconomic model of a fishery conducted on several stocks, a large stock capable of supporting a commercial fishery, and one or more smaller stocks which could be driven to extinction at harvest rates that the larger stock can sustain. The model permits a shifting of effort from a mixed-stock fishery to single-stock fisheries. Such a shift could save the weaker stocks from extinction, but the model highlights economic incentives to reject this option. This points to a fundamental conflict between the preservation of biodiversity and economic pressures to maximize profits. This fundamental conflict has in turn important consequences in current debates over the restructuring of major fisheries including those directed at Pacific salmon.     

Service Exchange Systems — The Stock Control of Repairable Items

In addition to stocks of spare parts for its machinery, an organization will often find it advantageous to hold stocks of repairable sub-assemblies. These can be used to shorten the repair and overhaul times of expensive machines. This paper describes extensions of standard stock control theory to the case of repairable items and also discusses some of the difficulties which can arise with service exchange systems in practice.     

基金“拥挤交易”对A股股价泡沫的影响研究

随着基金数量的不断增加,多家基金重仓一只股票所呈现的“拥挤交易”现象日渐明显。本文运用面板数据模型,对基金“拥挤交易”与A股股价泡沫之间的关系进行考察。结果表明,当公司超过6只基金重仓持股时,基金拥挤交易会对股价泡沫形成促进作用;当小于6只基金重仓持股时,这一关系则不显著。即:基金拥挤交易需要在“拥挤”到一定程度后才会促进股价泡沫膨胀。因此,管理层应高度重视6家以上基金重仓持股的股票,这类股票往往会形成较大的泡沫,同时也存在较大的崩溃风险。另外,管理层还应审慎研究政策出台时可能带来的预期,最大限度的避免基金经理产生一致的信念和一致行动,降低基金拥挤交易现象的发生。     

Decision making in stock trading: An application of PROMETHEE

The key issue for decision making in stock trading is selection of the right stock at the right time. In order to select the superior stocks (alternatives) for investment, a finite number of alternatives have to be ranked considering several and sometimes conflicting criteria. Therefore, we are faced with a special multicriteria decision-making problem. The purpose of this paper is to develop a decision-making model for selecting superior stocks in stock exchange and a model is provided in order to structure this problem. The proposed model is structured around two pillars: Industry evaluation and Company evaluation. The preference ranking organization method for enrichment evaluation (PROMETHEE) has been used for solving the problem. The model has been applied at Tehran Stock Exchange (TSE) as a real case and a survey from the experts in order to determine the effective criteria for industry evaluation and company evaluation has been conducted.     

Stochastic volatility asymptotics of stock loans: Valuation and optimal stopping

A stock loan, or equity security lending service, is a loan which uses stocks as collateral. The borrower has the right to repay the principal with interest and regain the stock, or make no repayment and surrender the stock. Therefore, the valuation of stock loan is an optimal stopping problem related to a perpetual American option with a negative effective interest rate. The negative effective interest rate makes standard techniques for perpetual American option pricing failure. Using a fast mean-reverting stochastic volatility model, we applied a perturbation technique to the free-boundary value problem for the stock loan price. An analytical pricing formula and optimal exercise boundary are derived by means of asymptotic expansion.     

COMPARING PROACTIVE AND REACTIVE MANAGEMENT: MANAGING A TRANSBOUNDARY FISH STOCK UNDER CHANGING ENVIRONMENT

Environmental change in general, and climate change in particular, can lead to changes in distribution of fish stocks. When such changes involve transboundary fish stocks, the countries sharing the stock need to reconsider their harvesting policies. We investigate the effects of changing stock distribution on the optimal fishing policies in a two players’ noncooperative game. We compare reactive management, under which the manager ignores future distributional shifts (knowingly or unknowingly), with proactive management where the manager considers such shifts in his decisions. A dynamic programming model is developed to identify closed‐loop Nash strategies. We show that the role of two players is symmetric under reactive management but asymmetric under proactive management where managers anticipate future changes in stock ownership. The player losing the stock tends to harvest more aggressively compared to the player gaining the stock who acts more conservatively. Strategic interactions show tendency for complementary actions that can change abruptly during the ownership transition. The differences between management regimes vary from quantitative to qualitative; differences are minimal for stocks with little or no schooling, whereas highly schooling stocks may avoid collapse only under proactive management.     

盈余信息预披露与股票价格行为的研究

从上证A股所有股票中选出了大公司股票与小公司股票各80家,以2002年—2004年为研究区间,通过构建计量经济模型来研究我国股市是否存在未预期的股票价格对盈余信息反映是公司规模的减函数,即“规模效应”.实证研究表明,我国上证A股市场不支持这一假说.说明了我国上市公司的会计信息含量还远远满足不了投资者的需求,若提高盈余报告时效性和盈余信息内容的可信性,才能增加投资者信息收集的动力,促进股票价值的理性回归,保护投资者利益.     

Concepts for safety stock determination under stochastic demand and different types of random production yield

We consider a manufacturer’s stochastic production/inventory problem under periodic review and present methods for safety stock determination to cope with uncertainties that are caused by stochastic demand and different types of yield randomness. Following well-proven inventory control concepts for this problem type, we focus on a critical stock policy with a linear order release rule. A central parameter of this type of policy is given by the safety stock value. When non-zero manufacturing lead times are taken into account in the random yield context, it turns out that safety stocks have to be determined that vary from period to period. We present a simple approach for calculating these dynamic safety stocks for different yield models. Additionally, we suggest approaches for determining appropriate static safety stocks that are easier to apply in practice. In a simulation study we investigate the performance of the proposed safety stock variants.     

BENEFITS AND RISKS OF INCREASED SPATIAL RESOLUTION IN THE MANAGEMENT OF FISHERY METAPOPULATIONS UNDER UNCERTAINTY

Abstract Stock assessments and harvest guidelines are typically based on the concept of a “fish stock,” which may encompass a very large area. The presence of discrete subpopulations within managed fish stocks presents risks and opportunities for fishery management. Failure to manage catch at the same scale as the true population structure can lead to extirpation of discrete subpopulations and to declines in the productivity of the larger metapopulation. However, it may be difficult and costly to assess and manage stocks at a finer spatial scale, and there is likely greater uncertainty about the size of substocks than about the aggregate stock. We use a two‐area simulation model to compare the performance of fishery management at different spatial resolutions when there is uncertainty about growth, the size of the total population, and the relative size of the subpopulations. We show that relative benefits of finer scale management, in terms of profits and risks of depleting subpopulations, depend on a number of biological, technical, and economic factors. In some cases it may be both less risky and more profitable to manage the fishery with a single total allowable catch, even when there are biologically separate fish populations in the two areas.     

Multi-period stochastic portfolio optimization: Block-separable decomposition

We consider a multiperiod stochastic programming recourse model for stock portfolio optimization. The presence of various risk and policy constraints leads to significant period-by-period linkage in the model. Furthermore, the dimensionality of the model is large due to many securities under consideration. We propose exploiting block separable recourse structure as well as methods of inducing such structure within nested L-shaped decomposition. We test the model and solution methodology with a base consisting of the Standard & Poor 100 stocks and experiment with several variants of the block separable technique. These are then compared to the standard nested period-by-period decomposition algorithm. It turns out that for financial optimization models of the kind that are discussed in this paper, significant computational efficiencies can be gained with the proposed methodology.     

The behavior of individual and aggregate stock prices

News about an individual stock normally has only a trivial impact on the aggregate economy. The news of the aggregate stock market, however, may have a significant impact on the prospects of the economy, and so has a large impact on the pricing kernel. This difference between the aggregate stock market and individual stocks is analyzed in a dynamic general equilibrium setting with incomplete information. The main findings are as follows. First, consistent with existing empirical evidence, the correlation between stock returns and earnings surprises is, on average, positive at the individual stock level and is lower or even negative at the aggregate level. Second, a stock’s return is less sensitive to its earnings surprises if the expected earnings growth of the stock is more pro-cyclical. Third, a decrease of information quality of a stock increases its risk premium if the stock accounts for a small fraction of the economy, but decreases its risk premium if the stock accounts for a large fraction.     

基于双重加权网络的股票强相关性分析

为分析股票间的强相关性,合理构建投资组合,选择中国股市煤炭电力板块93支股票,以股票上市时间至2011年2月11日每日收盘价和成交量,建立双重加权网络模型.在模型中,顶点是股票,双重边分别由股票间的成交量相关和回报相关建立,边上的权就是相关系数值.研究结果表明,网络顶点度服从幂律分布,负幂指数δ值约为0.02;单网络顶点度呈现"翘翘板"特点,即一个单网络中度大的顶点在另一个单网络中度很小;网络的模块具有同源性,即模块中顶点来自同一板块;网络的最大生成树明显以板块形成树分枝;网络树EGO结构体现企业间存在的生产材料和业务供求关系.     

基于成交量分解模型的改进VWAP策略

传统VWAP(交易量加权平均价格)策略通过拆分大额委托订单,跟踪市场成交均价,达到最小化冲击成本的目的,而准确预测成交量日内分布是运用VWAP策略的关键。通过详细考察现有的改进VWAP策略中成交量预测模型的建模方式和预测结果,发现由于无法分离成交量日内周期结构,现有模型样本依赖性较大且难以适用于多数股票。因此,本文从个股与市场成交量变化趋势的关系角度出发,推导个股成交量与市场趋势的关系,通过构造个股成交量关于市场因素的因子载荷,将日内成交量分解为市场共同部分和个股特殊部分,预测成交量日内分布并构建动态VWAP策略。实证结果表明新的成交量分解模型可以有效分离个股的成交量日内周期结构,在此基础上构造的改进VWAP策略不仅具有较为广泛的适用性,且跟踪误差减少幅度比现阶段同类型的改进VWAP策略更大,能更好的降低市场冲击成本。