基于随机波动的企业的最优组合投资策略

Merton的投资模型拓展到随机波动模型.在典型的动态规划中,投资问题中的值函数一般用Bellman方程的粘滞解表示.本文通过指数变换把偏微分方程转变成一个半线性的抛物线方程,并证明了其值函数连续解的存在性,在此基础上给出了企业的最优组合投资策略及一个投资的例子.     

跳-扩散风险模型的最优投资和再保险策略

本文对跳-扩散风险模型,在赔付进行比例再保险,以及盈余投资于无风险资产和风险资产的条件下,研究使得最终财富的指数期望效用最大的最优投资和比例再保险策略.得到最优投资策略和最优再保险策略,以及最大指数期望效用函数的显式表达式,发现最优策略和值函数都受到无风险利率的影响.最后通过数值计算,得到最优投资和比例再保险策略,以及值函数与模型各个参数之间的关系.     

Dynamic investment policy with installation experience effects

This paper analyzes the consequences of incorporating a learning-by-doing effect in the firm's adjustment cost function. The hypothesis is that, the larger the existing capital stock, the larger the installation experience gained, and therefore the smaller the cost of installing an additional unit of capital stock. The implications of the hypothesis are investigated in an optimal control model for the determination of the firm's optimal investment policy over an infinite planning period.The research of the second author was sponsored by a fellowship of the Royal Netherlands Academy of Arts and Sciences.     

教育经费投入对区域经济增长影响的实证研究

教育经费投入对于提升人力资本,促进经济增长有着无可代替的作用.通过利用改进的柯布道格拉斯生产函数和人力资本理论,运用2005-2011全国其中30个省级面板数据,对不同层次的教育经费投入与区域经济增长之间的关系进行了实证研究.研究结果表明,初等学校的教育经费投入对中国各区域的经济增长均有显著作用,高等职业学校的教育经费投入对东部和西部地区的经济增长作用显著,本科学校的教育经费投入对中部地区经济增长作用显著.     

投资项目的期权评价与最优投资规则

本文介绍了不确定环境下的投资项目的期权评价方法和最优投资规则，研究了单期项目和连续投资项目的投资决策问题，探讨了实物期权评价方法与传统的净现值评价方法中最优投资规则的差异，并对影响最优投资规则的差异因素进行了敏感性分析，得出了直观而有实用价值的结论。     

沉没成本约束条件下的最优跨地区投资组合数学分析

对沉没成本约束条件下的最优跨地区投资组合进行研究,并建立了一个包括商品市场和要素市场在内一般均衡的数学模型.模型的基本函数是S-D-S效用函数和C-D生产函数,这保证了本模型具有良好的可扩展性,并得到独到的结论是的沉没成本对投资的影响要大于利息.     

Optimal proportional reinsurance and investment for stochastic factor models

In this work we investigate the optimal proportional reinsurance-investment strategy of an insurance company which wishes to maximize the expected exponential utility of its terminal wealth in a finite time horizon. Our goal is to extend the classical Cramér–Lundberg model introducing a stochastic factor which affects the intensity of the claims arrival process, described by a Cox process, as well as the insurance and reinsurance premia. The financial market is supposed not influenced by the stochastic factor, hence it is independent on the insurance market. Using the classical stochastic control approach based on the Hamilton–Jacobi–Bellman equation we characterize the optimal strategy and provide a verification result for the value function via classical solutions to two backward partial differential equations. Existence and uniqueness of these solutions are discussed. Results under various premium calculation principles are illustrated and a new premium calculation rule is proposed in order to get more realistic strategies and to better fit our stochastic factor model. Finally, numerical simulations are performed to obtain sensitivity analyses.     

社会保障税的经济归宿分析

社会保障税的税负应由雇主与雇员共同分担,采用数理方法可以理论上推理出:在其他条件不变的情况下,雇主与雇员所分担的社会保障税税负比例为劳动供给弹性与未征税时劳动需求弹性.在政府设计社会保障税制度时,要减少征税成本与税负转嫁成本,以减少社会保障税对经济效率所产生的扭曲及其他负面影响;要结合现时劳动供求状况制定雇主与雇员的法定分担比例;社会保障税税率在短期内应是相对稳定的,但在长期内应是动态变化的.     

Impact of Technology Assimilation on Investment Policy: Dynamic Optimization and Econometric Identification

The paper introduces a dynamic model of optimization of R&D intensity under the effect of technology assimilation. The model involves R&D investments, technology stock, production, and technology productivity as main variables. The model characterizes the “growth” and “decline” trends that describe the interaction between R&D investments and transformation process of production factors. The technology stock is constructed as a function of indigenous and exogenous technology stocks and their growth rates. The research focuses on the issue of a reasonable balance between the indigenous technology stock and assimilated technology flow. Econometric linearization of the technology assimilation effect is used to construct a reasonable optimal control model. The existence of the value function for the problem of the optimal economic growth on the infinite horizon is proved and the basic features of the value function are outlined. The property of strong invariance for the main proportions of the model such as technology productivity and R&D intensity is proved. The model is calibrated on the aggregate data of the Japanese automotive industry. The research was sponsored by the SIMOT Program of the Japanese Ministry of Education, Science and Technology. The second author was supported by the Russian Fund for Basic Research, Grants 05-01-00601, 05-01-08034, by the Russian Fund for Humanities, Grant RFH 05-02-02118a, and by the Program for the Sponsorship of Leading Scientific Schools, Grant NSCH-791.2003.1.     

Optimal admission control for two station tandem queues with loss

We consider a two-station tandem queue with a buffer size of one at the first station and a finite buffer size at the second station. Silva et al. (2013) gave a criterion determining the optimal admission control policy for this model. In this paper, we improve the results of Silva et al. (2013) and also solve the problem conjectured by Silva et al. (2013).     

An Analogue of the Cramér–Lundberg Approximation in the Optimal Investment Case

We consider ruin probabilities for an insurance company, which can also invest in the stock market. The risk process is modeled by a compound Poisson process and the stock price by geometric Brownian motion. We show that if the tails of the claims are light tailed, then the optimal strategy is asymptotically given by holding a constant $-value in the stock position. Furthermore, we show that a kind of Cramér–Lundberg approximation holds for the minimal ruin probability. Everything is shown under assumptions, which are analogous to the assumptions in the case of the classical Cramér–Lundberg approximation without investment.     

Optimal Distributed Dynamic Advertising

We propose a novel approach to modeling advertising dynamics for a firm operating over a distributed market domain based on controlled partial differential equations of the diffusion type. Using our model, we consider a general type of finite-horizon profit maximization problem in a monopoly setting. By reformulating this profit maximization problem as an optimal control problem in infinite dimensions, we derive sufficient conditions for the existence of its optimal solutions under general profit functions, as well as state and control constraints, and provide a general characterization of the optimal solutions. Sharper, feedback-form characterizations of the optimal solutions are obtained for two variants of the general problem. The first author gratefully acknowledges financial support by the NSF, the DAAD, the SFB 611 (Bonn), and the Max-Planck-Institut für Mathematik (Leipzig) through an IPDE fellowship.     

均值-方差准则下的多期最优保险投资(英文)

近年来,最优保险投资问题吸引了越来越多的注意。一般这个问题是在连续时间框架下来研究的。本文针对这一问题建立离散时间的最优控制模型。应用动态规划原理求解模型对应的近似问题,得到了最优投资策略和投资有效边界的解析表达形式。本文得到的最优投资策略和投资有效边界均依赖于承保参数。通过数值例子分析了承保参数对最优投资策略和有效边界的影响。     

Dynamic Programming Method for Constrained Discrete-Time Optimal Control

A dynamic programming method is presented for solving constrained, discrete-time, optimal control problems. The method is based on an efficient algorithm for solving the subproblems of sequential quadratic programming. By using an interior-point method to accommodate inequality constraints, a modification of an existing algorithm for equality constrained problems can be used iteratively to solve the subproblems. Two test problems and two application problems are presented. The application examples include a rest-to-rest maneuver of a flexible structure and a constrained brachistochrone problem.     

企业研发投资的外部效应与最优补贴政策

本结合传统的企业研发决策理论，引入研发投资的外部效应，讨论了研发投资的不可撤回性、技术不确定性对企业研发投资决策、政府研发投资补贴政策和对撤资行为的税收政策的影响，并得出以下结论：政府补贴政策、税收政策与企业研发投资不可撤回性和技术不确定性无关，补贴率和税率的确定仅取决于研发投资外部性，且对研发投资的补贴率和对撤资行为征税的税率相等。     

Optimal Policies for Investment with Time-Varying Return Distributions

We develop a model in which investors must learn the distribution of asset returns over time. The process of learning is made more difficult by the fact that the distributions are not constant through time. We consider risk-neutral investors who have quadratic utility and are selecting between two risky assets. We determine the time at which it is optimal to update the distribution estimate and hence, alter portfolio weights. Our results deliver an optimal policy for asset allocation, that is, the sequence of time intervals at which it is optimal to switch between assets, based on stochastic optimal control theory. In addition, we determine the time intervals in which asset switching leads to a loss with high probability. We provide estimates of the effectiveness of the optimal policy.     

带交易费用的最优投资和比例再保险

研究了保险公司的最优投资和再保险问题.保险公司的盈余通过跳-扩散风险模型来模拟,可以把盈余的一部分投资到金融市场,金融市场由一个无风险资产和n个风险资产组成,并且保险公司还可以购买比例再保险;在买卖风险资产时,考虑了交易费用.通过随机控制的理论,获得了最优策略和值函数的显示解.     

含有随机波动的非线性的最优投资和消费模型

在连续时间模型假设下,研究风险资产价格服从一个带有随机波动的几何布朗运动的最优消费和投资问题．首先建立了最优消费和投资同题随机最优控制数学模型;然后运用随机最优控制理论,得到了最优投资和消费随机最优控制问题的值函数所满足的线性抛物线偏微分方程和非线性抛物线偏微分方程．     

Multiple Equilibria and Thresholds Due to Relative Investment Costs

A dynamic model of the firm is studied in which investment costs depend on the magnitude of the investment relative to the stock of capital goods. It is shown that in general nonunique steady states can exist which can be stable or unstable. It is possible that unstable steady states occur in the concave domain of the Hamiltonian. For a particular specification, a scenario occurs with two stable steady states and one unstable steady state. The two stable steady states are long run equilibria; which one of them is reached in the long run depends on the initial state. In case the Hamiltonian is locally concave around the unstable steady state, this steady state is the threshold that separates the domain of initial conditions that each of the stable steady states attracts. The unstable steady state is a node and investment is a continuous function of the capital stock. If the unstable steady state lies in the nonconcave domain of the Hamiltonian, this steady state can either be a node or a focus. Furthermore, continuity can (but need not) be retained similarly to the concave case, a fact which has been entirely overlooked in the literature.     

固定资产投资系统的稳定性分析及最优控制问题

给出带有时滞的一类固定资产模型，此模型为含有非局部和时滞边界条件的分布参数系统。通过Lyapunov函数，对系统的稳定性进行了分析，给出系统稳定的充分条件，然后，讨论了积累率的最优控制问题。根据Banach空间的一些理论，证明了其最优解的存在唯一性。