Stochastic Interest Rates and the Bond-Stock Mix

The optimal bond-stock mix is examined in light of an apparentinconsistency between the Tobin Separation Theorem and the adviceof popular investment advisors which has been pointed out byCanner et al. (1997).It is shown that the apparent inconsistencyis largely explicable in terms of the hedging demands of optimisinglong-term investors in an environment in which the investmentopportunity set is subject to stochastic shocks. The analysispoints to the importance of considering investors' time horizonsin analyzing optimal portfolio policies.     

Dividend Policy under Asymmetric Information

We extend the standard finance model of the firm's dividend/investment/financing decisions by allowing the firm's managers to know more than outside investors about the true state of the firm's current earnings. The extension endogenizes the dividend (and financing) announcement effects amply documented in recent research. But once trading of shares is admitted to the model along with asymmetric information, the familiar Fisherian criterion for optimal investment becomes time inconsistent: the market's belief that the firm is following the Fisher rule creates incentives to violate the rule. We show that an informationally consistent signalling equilibrium exists under asymmetric information and the trading of shares that restores the time consistency of investment policy, but leads in general to lower levels of investment than the optimum achievable under full information and/or no trading. Contractual provisions that change the information asymmetry or the possibility of profiting from it could eliminate both the time inconsistency and the inefficiency in investment policies, but these contractual provisions too are likely to involve dead-weight costs. Establishing which route or combination of routes serves in practice to maintain consistency remains for future research.     

On the Interaction of Real and Financial Decisions of the Firm Under Uncertainty

This study analyzes the interaction between the optimal level of investment and debt financing. For this purpose, a model is structured in which a firm, facing an uncertain price, has to decide on its optimal level of investment and debt. The amount of investment sets a limit on output whose optimal level is determined after price is realized. The debt involved is risky (there exists a possibility of bankruptcy). The analysis proves that investment and its optimal financing have to be simultaneously determined and that a negative relationship exists between operating and financial leverage. We also demonstrate that as the tax rate increases, optimal capacity decreases and optimal leverage increases. An analysis of the impact of changes in the expected price shows that under some conditions, an increase in expected price would lead to an increase in optimal investment (firm size) and a decrease in optimal debt.     

Private equity valuation under time-inconsistent preferences

Our research expands on the private equity (PE) valuation theory by incorporating the limited partner’s (LP) time-inconsistent preferences. Our findings show that time inconsistency has a detrimental impact on the LP’s certainty-equivalent valuation, which is dependent on the duration of investment and the value of PE asset. Through a comparative static analysis of the risk-attitude parameter and the future self arrival intensity, we have determined that the negative effects of time inconsistency can be mitigated by a more conservative attitude on the part of LP, while a higher future self arrival intensity exacerbates the impact of LP’s time inconsistency on their certainty-equivalent valuation.     

Debt overhang and non-distressed debt restructuring

In this paper, we analyse the restructuring of debt in the presence of debt overhang. The firm starts out with a debt liability and an investment opportunity. Then with unrestructured debt, the firm maintains the current borrowing payments until default or investment. If the creditors allow the parties to restructure the debt with exchange offers, then the borrowing payments change as well as the default and investment points. We find that there is a unique optimal restructuring path which maintains debt at positive levels but defers default indefinitely. This path is optimal regardless of whether the debt holders or the firm control the process through superior bargaining power. Moreover, a debt-for-equity exchange to remove all existing debt takes place just before investment that is followed by the issue of an optimal amount of new debt as part of the funding for the investment cost. The optimal investment trigger is higher along the optimal restructuring path than it is for an unlevered firm. We discuss the findings in the light of existing empirical evidence.     

Allocations and Common Costs in Long-Run Investing and Pricing Decisions: An Historical Analysis

The extent to which allocated common costs should influence business decisions remains controversial in management accounting. In the finance and investment literature this issue is generally ignored or dismissed by appeals to the'incremental' principle. This article presents an historical analysis of allocations in long-run investing and pricing decisions. It is demonstrated that seminal figures in the development of both investment and price theory were conscious of the need for firms to cover common costs and generally favoured some form of allocation. The anti-allocationist position is shown to be of relatively recent origin and to have caused an inconsistency in the management accounting literature in the treatment of common costs. European costing theory is shown to have been consistently allocationist. Evidence of a return in the recent U.S. literature to the older Anglo-American, and continuing European, allocations tradition is presented.     

The Underinvestment and Overinvestment Hypotheses: an Analysis Using Panel Data

We study the relationship between firm value and investment to test the underinvestment and overinvestment hypotheses. The results obtained, using panel data methodology as the estimation method, indicate that the abovementioned relation is quadratic, which implies that there exists an optimal level of investment. As a consequence, firms that invest less than the optimal level suffer from an underinvestment problem, while those investing more than the optimum suffer from overinvestment. The quadratic relation is maintained when firms are classified depending on their investment opportunities, the optimum being in accordance with the quality of investment opportunities.     

上市公司现金持有水平对投资行为影响研究

企业持有现金是企业内部融资的一个重要手段,与投资行为密切相关。上市公司应持有多大规模的现金,才能使得现金持有成本和丧失投资机会的成本之和最低,这是企业管理层必须考虑的一个问题。该文旨在通过实证方法研究不同现金持有水平的公司在投资行为方面存在的差异以及投资效率的高低,并提出相应的建议对策,以期能够对公司的现金持有管理有所贡献。     

论技术创新的最优市场结构 ——关于熊彼特猜想的研究

当技术创新的市场收益率随着参与技术创新企业数量的增加而最终递减时,存在一个可以导致技术创新企业创新收益最大化的最优市场结构即最优技术创新企业的数量。如果企业技术创新存在边际收益递减现象,则存在一个导致技术创新投入最大化的最优市场结构,这一最优市场结构将因技术创新风险的提高而降低。技术创新收益最大化的市场结构与技术创新投入最大化的市场结构之间构成了能够有效促进技术创新的最优市场结构区间。     

Optimal mortgage contracts with time-inconsistent preferences

This paper integrates a time-inconsistent preference into the mortgage design problem and studies the corresponding effects on the optimal contract. By assuming exogenous time inconsistency in borrower's preference, we find that the time-inconsistent preference increases the loss in the lender's value and the compensation boundary. We implement the optimal contract using standard securities and option adjustable-rate mortgages (ARMs). The findings show that the time-inconsistent preference increases the default rate, and relative to standard securities, option ARMs increase the total debt capacity, but the borrower's time inconsistency can lead to sudden jumps in the total debt capacity. We also consider the endogenous time inconsistency in the borrower's preference and derive the corresponding mortgage contract; we find that a lender can perfectly offset the effect of a borrower's time inconsistency on the value function and compensation strategy. The liquidation boundary at the low interest rate varies with the degree of time inconsistency, explaining the heterogeneity in mortgage default behaviors observed in practice.     

Consumption–investment optimization with Epstein–Zin utility in incomplete markets

In a market with stochastic investment opportunities, we study an optimal consumption–investment problem for an agent with recursive utility of Epstein–Zin type. Focusing on the empirically relevant specification where both risk aversion and elasticity of intertemporal substitution are in excess of one, we characterize optimal consumption and investment strategies via backward stochastic differential equations. The superdifferential of indirect utility is also obtained, meeting demands from applications in which Epstein–Zin utilities were used to resolve several asset pricing puzzles. The empirically relevant utility specification introduces difficulties to the optimization problem due to the fact that the Epstein–Zin aggregator is neither Lipschitz nor jointly concave in all its variables.     

Optimal Sequential Investment When Capital is Not Readily Reversible

When investment opportunities arrive one at a time and are reviewed sequentially, a corporation's optimal policy differs from a standard net present value rule if the corporation exercises control over an industry state variable and control is costly. The first condition presupposes a degree of market power for the firm; the second occurs if corporate investment decisions are imperfectly reversible. To address the problem of optimal investment in this context, a firm's investment decisions are modeled as a Markov reward process. The causes of economic irreversibility are discussed and general propositions concerning the optimal investment policy are derived. These propositions are then applied to the optimization of an exploration program by an oligopolistic firm (a price leader). Under particular demand and distributional assumptions, solutions for the optimal decision rule and the value of the exploration program are obtained and their properties examined.     

Conditions for rational investment short-termism

In this paper we examine the theoretical conditions under which a firm will have incentives to optimally choose investment projects of duration that deviates from its stated horizon objective. Our approach considers a context in which investment horizon is subject to randomness and its length is optimally chosen by each firm??s manager so that to maximize his/her objective function in the form of expected wage. Our framework derives the distribution of optimal horizon choices for which all managers would obtain the same level of expected wage. It is shown that the presence of asymmetric loss preferences in the form of higher costs from managers?? investment duration over-statements (under-statements), results in a shift of the distribution of optimal durations to the left (right), thus making investment short-termism (long-termism) more likely to appear. The degree of the shift and the shape of the distribution of optimal investment durations depend on the trade-offs between preference asymmetries and the shape of the data generating process.     

基于规模与风格的证券投资基金最优组合构建研究

本文选择中国2004年10月1日前成立的8种投资风格共133只证券投资基金,根据其在2005年1月1日-2008年3月31日共161周的数据,依照非回置等权抽样方法构建基金组合。在研究了基金组合规模与组合风险和绩效关系的基础上,着重探讨了基金组合所含风格类型以及基金组合风格丰富化指标与组合风险和绩效的关系。在上述研究的基础上,论文提出了综合规模和风格双因素的基金最优组合构建原则,并得出了最适度风格类型模型和最适度风格丰富化指标模型。     

Optimal consumption and investment for markets with random coefficients

We consider an optimal investment and consumption problem for a Black–Scholes financial market with stochastic coefficients driven by a diffusion process. We assume that an agent makes consumption and investment decisions based on CRRA utility functions. The dynamic programming approach leads to an investigation of the Hamilton–Jacobi–Bellman (HJB) equation which is a highly nonlinear partial differential equation (PDE) of the second order. By using the Feynman–Kac representation, we prove uniqueness and smoothness of the solution. Moreover, we study the optimal convergence rate of iterative numerical schemes for both the value function and the optimal portfolio. We show that in this case, the optimal convergence rate is super-geometric, i.e., more rapid than any geometric one. We apply our results to a stochastic volatility financial market.     

Maturity and exercise price of executive stock options

Using a simple three-period model in which a manager can gather information before making an investment decision, this paper studies optimal contracts with various stock options. In particular, we show how the exercise price of executive stock options is related to a base salary, the size of the option grant, leverage, and the riskiness of a desired investment policy. The optimal exercise price increases in the size of grant and the base salary and decreases in leverage and the riskiness of a desired investment policy. Other things equal, the optimal exercise price of European options with a longer maturity should increase more for an increase in the base salary and the size of grant and decrease more for an increase in leverage than the one with a shorter maturity. The optimal exercise price of American options is determined by the optimal exercise prices of European options with different maturities. Given the fixed exercise price, the size of the option grant does not decrease in the face value of debt.     

Minimizing the lifetime ruin under borrowing and short-selling constraints

In this paper, the optimal investment strategies for minimizing the probability of lifetime ruin under borrowing and short-selling constraints are found. The investment portfolio consists of multiple risky investments and a riskless investment. The investor withdraws money from the portfolio at a constant rate proportional to the portfolio value. In order to find the results, an auxiliary market is constructed, and the techniques of stochastic optimal control are used. Via this method, we show how the application of stochastic optimal control is possible for minimizing the probability of lifetime ruin problem defined under an auxiliary market.     

Risk-Shifting Incentives and Signalling Through Corporate Capital Structure

This paper examines optimal corporate financing arrangements under asymmetric information for different patterns of temporal resolution of uncertainty in the underlying technology. An agency problem, a signalling problem and an agency-signalling problem arise as special cases. The associated informational equilibria and the optimal financing arrangements are characterized and compared. In the agency-signalling equilibrium the private information of corporate insiders at the time of financing is signalled through capital structure choices which deviate optimally from agency-cost minimizing financing arrangements, which in turn induce risk-shifting incentives in the investment policy. In the pure signalling case the equilibrium is characterized by direct contractual precommitments to implement investment policies which are riskier than pareto-optimal levels. Empirical implications for debt covenants and the announcement effect of investment policies and leverage increasing transactions on existing stock and bond prices are explicitly derived.     

保险公司资产组合与最优投资比例研究

保险公司收益主要来源于承保利润和投资收益,其中承保利润受政策变动、市场条件等外部环境的影响较大,而投资收益则更多地取决于保险公司的投资能力,因此保险公司如何构建资产组合、如何确定最优投资比例就是获取投资收益最大化的重要因素。本文通过理论推导得出了保险公司的资产组合模型并运用非线性规划求解出最优投资比例,进而根据保险公司的投资数据进行了实证研究,为我国保险公司的资产组合及最优投资比例提供了一个可借鉴的思路。     

A negative report on the ‘near optimality’ of the max-expected-log policy as applied to bounded utilities for long lived programs

Much controversy surrounds the use of the portfolio investment rules induced by maximizing the expected logarithm of terminal wealth (henceforth referred to as the MEL policy). It has been thought that the MEL policy is a good approximation to the optimal investment program when the utility of terminal wealth function is bounded and when the time horizon is long. However, I exhibit a class of bounded utility of terminal wealth functions for which the MEL policy is a very poor approximation to the optimal program. Hence, the wholesale use of the MEL policy as an approximation to the optimal program is unwarranted.