中央环保督察背景下地方政府环境管制行为研究

中央环保督察对环境的改善效果备受肯定,但是这种改善效果的持续性却受到质疑。基于演化博弈理论,本文构建了地方政府和污染企业的动态复制系统,探究中央环保督察压力下空气质量改善的途径。研究结果表明:中央环保督察过程中,空气质量的改善可能来自于地方政府无差别的关停污染企业;中央政府一味地加大对地方政府环保失职的惩罚,可能会导致地方政府采取一刀切式的“懒政”、“怠政”行为;辖区的初始污染水平、管制成本均影响地方政府的行为选择。地方政府一刀切行为是多因素驱动的结果,中央政府应协调各方力量,理性决策,推动中央环保督察的良性运行。     

基于动态VaR约束与随机波动率模型的最优投资策略

研究Stein-Stein随机波动率模型下带动态VaR约束的最优投资组合选择问题. 假设投资者的目标是最大化终端财富的期望幂效用,可投资于无风险资产和一种风险资产, 风险资产的价格过程由Stein-Stein随机波动率模型刻画. 同时, 投资者期望能在投资过程中利用动态VaR约束控制所面对的风险.运用Bellman动态规划方法和Lagrange乘子法, 得到了该约束问题最优策略的解析式及特殊情形下最优值函数的解析式; 并通过理论分析和数值算例, 阐述了动态VaR约束与随机波动率对最优投资策略的影响.     

碳排放约束下政府与企业的stackelberg决策分析

在碳排放约束额不能由政府单独决定的条件下,本文通过Stackelberg博弈模型分析了非集中决策系统中政府与企业对绿色技术的决策行为。对政府而言,在考虑以社会福利为目标的基础上引入了社会对环境的关注度,并分析了该因素对政府决策的影响。对企业而言,分析结果表明企业对绿色技术的选择并不随着约束值单调变化。当考虑技术成本对博弈双方决策的影响,发现企业对绿色技术的选择是由技术成本和产品经济效益对成本的补偿程度决定的。最后,综合考虑博弈双方的决策,本文讨论了政府能否通过适当的约束值来促使企业选择更好的绿色技术,并给出了建议。     

生态工业园企业排污行为选择及政府作用分析

环境污染问题日趋严重,生态工业园区的发展是缓解环境问题的重要途径之一.首先,采用演化博弈理论工具,分别研究了生态工业园企业、非生态园工业园企业排污行为与政府审查行为的博弈演化规律.其次,探讨了生态工业园中,政府通过制定合适的排污上限,督促企业减少排污总量问题.最后,用算例进行验证.结论表明,根据企业和政府所处的不同初始状态,政府应制定不同的奖励和惩罚措施引导企业加入生态工业园;当政府审查企业排污量的成本与对企业的奖励支出之和大于零时,政府应结合地方实际情况,制定"宽松"或"严格"的排污上限督促企业减少排污量.     

VaR约束下最优比例再保险和投资策略问题

研究了VaR动态约束下保险人的最优投资和再保险策略选择问题.假设保险人选择比例再保险来分散索赔风险,并通过银行存款和投资股票的手段来增加额外收益,其中股票价格满足Heston模型.保险人的目标是寻求使其终端财富的期望效用最大的最优策略.引入VaR约束条件并采用期望效用最大化为准则,运用随机控制理论建立具有VaR约束的随机控制问题,采用动态规划推导HJB方程,并利用Lagrange函数等方法得到指数效用下VaR约束有效和无效时的最优策略.另外,考虑了仅投资情形下的最优投资策略.最后通过仿真对最优策略进行敏感性分析.     

跳扩散市场投资组合研究

研究了连续时间动态均值-方差投资组合选择问题.假设风险资产价格服从跳跃-扩散过程且具有卖空约束.投资者的目标是在给定期望终止时刻财富条件下,最小化终止时刻财富的方差.通过求解模型相应的Hamilton-Jacobi-Bellmen方程,得到了最优投资策略及有效前沿的显示解.结果显示,风险资产的卖空约束及价格过程的跳跃因素对最优投资策略及有效前沿的是不可忽略的.     

阈值风险下的多企业合作治理污染的演化博弈分析

针对环境污染具有跨区域性,环境资源的公共物品属性,由单一产污企业治理污染物难以取得有效成果,辖区内多个产污企业合作治理是环境保护的必由之路。 本文从演化博弈论的研究视角探讨了多个排污企业之间的决策演化过程,建立了多主体演化博弈模型,并考虑了污染排放总量超过总量阈值时的环境恶化风险,研究阈值风险对产污企业合作治理污染策略选择的影响。 研究结果表明,较高的治理成本很大地约束了逐利企业治理污染的行为选择,造成公地悲剧的社会问题。 企业治污成本较大背景下,环境阈值风险发生概率越高,越能有效促进合作治理环境策略的演化稳定,合作治理占优于不治理。 出于对企业自身初始禀赋的保护,产污企业初始禀赋越大、排污收费率越高,越能有效促进企业治理污染物的积极性。 最后,为促进辖区内污染企业合作治理污染提出了政策建议。     

市场与规制双重不确定下企业环境投资行为选择

通过主体适应性规则构建企业环境投资行为模型,从政府环境规制和市场波动等方面刻画企业环境投资决策面临的不确定性,基于计算实验方法探寻企业在基准、震荡、上涨与下跌等4种情景下的环境投资行为规律。研究发现:政府规制强度越强,企业环境投资越充分,但投资偏差现象越明显。在震荡情景中,企业的环境投资行为表现出非理性状态,在上涨情景中,企业环境投资表现出过度反应。当市场产品价格波动处在单边行情,政府可以通过较为宽松的环境规制实现目标,而当市场产品价格处在震荡波动时,政府需要通过较为严格的环境规制刺激企业进行环境投资。企业的环境投资受到政府规制与市场信号的共同影响,政府的环境规制稳定的持续刺激并不会让企业盲目投资,但政府环境规制的频繁变动却会使企业无所适从。     

集权制下闭环供应链网络最优内生污染税问题

为激励生产企业积极参与逆向物流活动、自发回收处理废旧产品,对其废旧产品的排放实施税收政策是控制污染的一项有效措施.通过对闭环供应链网络中各决策者间相互关系的分析,并结合环境政策,建立集权制下废旧产品排放内生污染税均衡模型,研究网络中各主体的竞争行为及均衡条件,解决集权制下既能使网络中各主体利润最大化又能达到预期环境目标的废旧产品排放内生污染税设计问题,并全面分析环境政策的变化对网络中各主体的产品生产量、交易量、交易价格、需求量和废旧产品回收量等经济指标的影响.     

Heston随机波动率市场中带VaR约束的最优投资策略

本文研究了Heston随机波动率市场下, 基于VaR约束下的动态最优投资组合问题。
假设Heston随机波动率市场由一个无风险资产和一个风险资产构成,投资者的目标为最大化其终端的期望效用。与此同时, 投资者将动态地评估其待选的投资组合的VaR风险,并将其控制在一个可接受的范围之内。本文在合理的假设下,使用动态规划的方法,来求解该问题的最优投资策略。在特定的参数范围内,利用数值方法计算出近似的最优投资策略和相应值函数, 并对结果进行了分析。     

Marketable permits in a stochastic dynamic model of the firm

This contribution attempts to determine the effects of environmental regulation on the growth of an individual firm. Here, it is assumed that the firm revenue is stochastic. The government tries to reduce pollution by creating a market on which the firm has to buy permits in order to be allowed to pollute the environment.Pollution is an inevitable byproduct of the firm production process, and in our model the firm is offered two ways to deal with it. The first is to buy marketable permits, and the second is to clean up pollution which can be achieved through investing in abatement capital stock.It turns out that the firm optimal trajectory consists of at most seven different policies. They can be depicted in a feedback diagram from which we can conclude that, provided that the firm never faces a shortage of cash, productive and abatement capital stocks ultimately reach their equilibrium levels where marginal revenue equals marginal costs.This paper was presented at EURO XIII, July 19–22, 1994 in Glasgow, Scotland. The research of the second author has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences. Thanks are due to M. Stimming for valuable comments and suggestions and to A. Van Den Elzen for his corrections.     

Effects of pollution restrictions on dynamic investment policy of a firm

The purpose of this paper is to determine the effects of different pollution standards on the firm's resource allocation decisions. To do so, a dynamic model of the firm is developed in which it is assumed that production causes pollution as an inevitable byproduct. Concerning its investment policy, we suppose that the firm can choose between investing in productive capital goods and investing in abatement efforts.It is shown that, in some cases, future abatement expenses have a negative impact on the present level of productive investment, even if the pollution standard is not binding at the moment. This implies a really dynamic optimal investment policy for the firm, which cannot be obtained within a comparative static analysis.This research has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences. Comments by Frank van der Duyn Schouten and Piet Verheyen (Tilburg University) and by Raymond Gradus (Dutch Ministry of Finance, The Hague) are gratefully acknowledged.     

Dynamic Control and Optimization of Capital-Constrained Stochastic Inventory Systems

For most firms,especially the small-and medium-sized ones,the operational decisions are affected by their internal capital and ability to obtain external capital.However,the majority of the current studies on dynamic inventory control ignore the firm’s financial status and financing issues completely.An important question that arises is:what are the dynamic optimal inventory and financing policies for firms with limited capital and limited access to external capital?In this paper,we review some of the latest developments in this area.After a brief review of single period models,we focus on multi-period dynamic control of the firm who aims to optimize its xpected terminal wealth.Two cases are discussed in detail:self-finance and short term finance.In the first case,the firm has to rely on its own capital for all ordering decisions,while in the second,the firm can borrow short term loan from lenders.A detailed characterization of the optimal policy is presented and its managerial insights are discussed.Several possible extensions are suggested.     

Measuring dynamic efficiency: Theories and an integrated methodology

Almost all dynamic production systems are subject to lagged productive effects, which are an often-ignored latent source of interference in the efficiency measuring process. Existing data envelopment analysis (DEA) approaches rely on a static production environment. They can easily lead to biased evaluation results due to the erroneous assumption. To tackle this issue, this paper develops a dynamic DEA model that allows intertemporal effects in efficiency measuring. Specifically, the dynamic DEA model incorporates dynamic factors via a linear parametric formulation. Our model can be applied in place of static DEA models to a wide range of applications, such as analyzing longitudinal firm performance and productivity changes. As for the empirical efficiencies, we demonstrate how the lag parameters in the dynamic model can be estimated by the panel vector autoregressive model (PVAR). We use our methodology to evaluate advertising efficiencies of several major automobile and pharmaceutical firms in North America. The result shows that using static DEA in dynamic production can lead to both rank reversals and changes in efficiency scores.     

Competitive production scheduling: A two-firm,noncooperative finite dynamic game

In this paper, we study the production scheduling problem in a competitive environment. Two firms produce the same product and compete in a market. The demand is random and so is the production capacity of each firm, due to random breakdowns. We consider a finite planning horizon. The scheduling problem is formulated as a finite dynamic game. Algorithms are developed to determine the security, hazard, and Nash policies. Numerical examples are discussed. A single-firm optimization model is also analyzed and it is observed that the production control policy from the single-firm optimization model may not perform well in a competitive environment.     

Stocking and pricing decisions under endogenous demand and reference point effects

In this paper, we study the newsvendor’s pricing and stocking decisions under reference point effects. The demand faced by the newsvendor is endogenous and the customers may also decide to procure the product from an outside option. We characterize the firm’s optimal pricing and stocking decisions. Our analysis reveals a threshold policy on the firm’s ordering and pricing decisions while considering the impact of reference point effects. We also find that as the level of optimism increases, the firm’s optimal ordering level decreases and optimal price increases. We further study the impact of loss aversion on the firm’s ordering and pricing decisions.     

On Kirk's asymptotic contractions

Recently Kirk introduced the notion of asymptotic contractions on a metric space and using ultrapower techniques he obtained an asymptotic version of the Boyd-Wong fixed point theorem. In this paper we extend this result and moreover, we give a constructive proof of it. Furthermore, we obtain a complete characterization of asymptotic contractions on a compact metric space. As a by-product we establish a separation theorem for upper semicontinuous functions satisfying some limit condition.     

增长期权对最优资本结构的影响研究：企业生命周期的视角

资产构成和生命周期的动态关系决定了企业最优资本结构的变化趋势。本文在利息税盾和破产成本的权衡理论框架下,运用实物期权方法,理论上揭示了增长期权动态执行导致最优资本结构随企业生命周期的变化规律,扩展分析了股东-债权人代理冲突对最优资本结构的影响,并提供了基于中国沪深A股上市公司的经验证据。结果表明：随着企业由年轻走向成熟,增长期权不断执行和在位资产逐渐累积会降低企业总体的破产风险,从而企业最优财务杠杆呈现上升趋势且增长速度逐渐放缓;股东和债权人在增长期权执行决策上的代理冲突导致的投资不足会降低最优财务杠杆,但代理成本随企业生命周期推进呈递减趋势。     

Capital adequacy and risk management in banking industry

The present paper deals with the issue of bank capital adequacy and risk management within a stochastic dynamic setting. In particular, an explicit risk aggregation and capital expression is provided regarding the portfolio choice and capital requirements special context. Such a framework leads to a nonlinear stochastic optimal control problem whose solution may be determined by means of dynamic programming algorithm. The pertaining analysis relies heavily on the stochastic dynamic modeling of such balance sheet items as securities, loans, and regulatory capital with stochastic interest rates. In this respect, the special Kalman filter approach is used for the purpose of estimating the model parameters. The reached findings reveal well that the Tunisian bank, subject of study, generally exceeds the minimum requirements and is adequately capitalized to maintain the appropriate capital amount level commensurate with the aggregate risk. Besides, empirical evidence on the regulations' impact on driving bank capitalization and risk‐taking behavior has also been highlighted. Copyright © 2015 John Wiley & Sons, Ltd.     

Optimal dividend payments in the stochastic Ramsey model

We consider the dividend payments of a self-financing firm in the stochastic Ramsey model. The firm invests in capital stock and its production technology is given by the Cobb–Douglas function. Our objective is to maximize the expected present value of future real dividends subject to a positive constraint on the capital stock. We use the penalization method to obtain a solution for the variational inequality associated with the optimal growth problem and give a synthesis of the optimal dividend policy.