Asset management with endogenous withdrawals under a drawdown constraint

Asset preservation is a major concern for foundations that are hostile to large wealth downfalls. Implications for optimal consumption and investment policies are explored in a dynamic setting where wealth is restrained from falling below a fraction of its all-time high. Risky investment regulates wealth growth and mitigates the ratchet effect of the constraint, and may decrease as wealth approaches its maximum. The correspondence found between habit formation over consumption and wealth ratcheting provides a rational explanation for the proliferation of capital protection oriented funds.     

Portfolio selection with a drawdown constraint

When identifying optimal portfolios, practitioners often impose a drawdown constraint. This constraint is even explicit in some money management contracts such as the one recently involving Merrill Lynch’ management of Unilever’s pension fund. In this setting, we provide a characterization of optimal portfolios using mean–variance analysis. In the absence of a benchmark, we find that while the constraint typically decreases the optimal portfolio’s standard deviation, the constrained optimal portfolio can be notably mean–variance inefficient. In the presence of a benchmark such as in the Merrill Lynch–Unilever contract, we find that the constraint increases the optimal portfolio’s standard deviation and tracking error volatility. Thus, the constraint negatively affects a portfolio manager’s ability to track a benchmark.     

Optimal portfolios under a correlation constraint

Under a correlation constraint the optimal constant/fixed-mix portfolio consists of the market portfolio, the riskless bond and the benchmark     

Optimal insurance contract under a value-at-risk constraint

This study develops an optimal insurance contract endogenously under a value-at-risk (VaR) constraint. Although Wang et al. [2005] had examined this problem, their assumption implied that the insured is risk neutral. Consequently, this study extends Wang et al. [2005] and further considers a more realistic situation where the insured is risk averse. The study derives the optimal insurance contract as a single deductible insurance when the VaR constraint is redundant or as a double deductible insurance when the VaR constraint is binding. Finally, this study discusses the optimal coverage level from common forms of insurances, including deductible insurance, upper-limit insurance, and proportional coinsurance. JEL Classification G22     

Optimal proportional reinsurance to minimize the probability of drawdown under thinning-dependence structure

Abstract

In this paper, we consider the optimal proportional reinsurance problem in a risk model with the thinning-dependence structure, and the criterion is to minimize the probability that the value of the surplus process drops below some fixed proportion of its maximum value to date which is known as the probability of drawdown. The thinning dependence assumes that stochastic sources related to claim occurrence are classified into different groups, and that each group may cause a claim in each insurance class with a certain probability. By the technique of stochastic control theory and the corresponding Hamilton–Jacobi–Bellman equation, the optimal reinsurance strategy and the corresponding minimum probability of drawdown are derived not only for the expected value principle but also for the variance premium principle. Finally, some numerical examples are presented to show the impact of model parameters on the optimal results.     

Optimal asset allocation for participating contracts under the VaR and PI constraint

ABSTRACT

Participating contracts provide a maturity guarantee for the policyholder. However, the terminal payoff to the policyholder should be related to financial risks of participating insurance contracts. We investigate an optimal investment problem under a joint value-at-risk and portfolio insurance constraint faced by the insurer who offers participating contracts. The insurer aims to maximize the expected utility of the terminal payoff to the insurer. We adopt a concavification technique and a Lagrange dual method to solve the problem and derive the representations of the optimal wealth process and trading strategies. We also carry out some numerical analysis to show how the joint value-at-risk and the portfolio insurance constraint impacts the optimal terminal wealth.     

Optimal portfolio allocation under the probabilistic VaR constraint and incentives for financial innovation

We characterize the investor’s optimal portfolio allocation subject to a budget constraint and a probabilistic VaR constraint in complete markets environments with a finite number of states. The set of feasible portfolios might no longer be connected or convex, while the number of local optima increases exponentially with the number of states, implying computational complexity. The optimal constrained portfolio allocation may therefore not be monotonic in the state–price density. We propose a type of financial innovation, which splits states of nature, that is shown to weakly enhance welfare, restore monotonicity of the optimal portfolio allocation in the state-price density, and reduce computational complexity. We are grateful to Ken Kavajecz and seminar participants at Harvard Business School, London School of Economics, Maastrict University, ZEI Bonn, and Danske Bank Symposium on Asset allocation and Value-at-Risk: Where Theory Meets Practice for comments on an earlier version of this paper. We also benefitted from the suggestions of two anonymous referees. Our papers can be downloaded from www.RiskResearch.org.     

Fast swaption pricing under the market model with a square-root volatility process

In this paper we study a correlation-based LIBOR market model with a square-root volatility process. This model captures downward volatility skews through taking negative correlations between forward rates and the multiplier. An approximate pricing formula is developed for swaptions, and the formula is implemented via fast Fourier transform. Numerical results on pricing accuracy are presented, which strongly support the approximations made in deriving the formula.     

Optimal design of equity-linked products with a probabilistic constraint

There is a rich variety of tailored investment products available to the retail investor. These products combine upside participation in bull markets with downside protection in bear markets. Examples include the equity-linked products sold by insurance companies and the structured products marketed by banks. This paper examines a particular contract design for products of this nature. The paper finds the optimal design from the investor's viewpoint. It is assumed that the investor wishes to maximize expected utility of the terminal wealth subject to certain constraints. These constraints include a guaranteed rate of return as well as the opportunity to outperform a benchmark portfolio with a given probability. We derive the explicit form of the optimal design assuming both constraints apply and we illustrate the nature of the solution using some specific examples.     

Portfolio optimisation under non-linear drawdown constraints in a semimartingale financial model

A drawdown constraint forces the current wealth to remain above a given function of its maximum to date. We consider the portfolio optimisation problem of maximising the long-term growth rate of the expected utility of wealth subject to a drawdown constraint, as in the original setup of Grossman and Zhou (Math. Finance 3:241–276, 1993). We work in an abstract semimartingale financial market model with a general class of utility functions and drawdown constraints. We solve the problem by showing that it is in fact equivalent to an unconstrained problem with a suitably modified utility function. Both the value function and the optimal investment policy for the drawdown problem are given explicitly in terms of their counterparts in the unconstrained problem.     

Optimal investment-reinsurance with dynamic risk constraint and regime switching

We study an optimal investment–reinsurance problem for an insurer who faces dynamic risk constraint in a Markovian regime-switching environment. The goal of the insurer is to maximize the expected utility of terminal wealth. Here the dynamic risk constraint is described by the maximal conditional Value at Risk over different economic states. The rationale is to provide a prudent investment–reinsurance strategy by taking into account the worst case scenario over different economic states. Using the dynamic programming approach, we obtain an analytical solution of the problem when the insurance business is modeled by either the classical Cramer–Lundberg model or its diffusion approximation. We document some important qualitative behaviors of the optimal investment–reinsurance strategies and investigate the impacts of switching regimes and risk constraint on the optimal strategies.     

Optimal investment of an insurer with regime-switching and risk constraint

We investigate an optimal investment problem of an insurance company in the presence of risk constraint and regime-switching using a game theoretic approach. A dynamic risk constraint is considered where we constrain the uncertainty aversion to the ‘true’ model for financial risk at a given level. We describe the surplus of an insurance company using a general jump process, namely, a Markov-modulated random measure. The insurance company invests the surplus in a risky financial asset whose dynamics are modeled by a regime-switching geometric Brownian motion. To incorporate model uncertainty, we consider a robust approach, where a family of probability measures is cosidered and the insurance company maximizes the expected utility of terminal wealth in the ‘worst-case’ probability scenario. The optimal investment problem is then formulated as a constrained two-player, zero-sum, stochastic differential game between the insurance company and the market. Different from the other works in the literature, our technique is to transform the problem into a deterministic differential game first, in order to obtain the optimal strategy of the game problem explicitly.     

Tax treatment of dividends and capital gains and the dividend decision under dual income tax

The paper analyses efficiency aspects of a dual income tax system with a higher tax on capital gains than dividends. It argues that apart from the distortions to investments claimed in earlier literature, the system puts even more emphasis in creating incentives for entrepreneurs to participate in tax planning. The paper suggests that the owner of a closely held company can avoid all personal taxes on entrepreneurial income by two tax-planning strategies. The first is the avoidance of distributions, which would be taxed at the tax rate on labour income. These funds would instead be invested in the financial markets. The second strategy is a distribute and call-back policy, converting retained profits into new equity capital. Interestingly, the outcome is that investment in real capital is not distorted in the long-run equilibrium. Empirical evidence using microdata is also provided.      

On capital injections and dividends with tax in a diffusion approximation

We consider a diffusion approximation to a risk process with dividends and capital injections. Tax has to be paid on dividends, but capital injections lead to an exemption from tax. That is, tax is only paid for the aggregate excess of dividends over the capital injections. The value of a strategy is the expected value of the discounted dividend payments after tax minus the discounted capital injections. We solve the problem and show that the optimal dividend strategy is a barrier strategy.     

The square-root law,uncertainty and international reserves under alternative regimes: Canadian experience, 1950–1976

A transactions-precautionary model of demand for international reserves is developed and tested against Canadian data. The results indicate that: (i) the demand for reserves is characterized by economies of scale with respect to the volume of transactions that are invariant to the exchange rate regime, but (ii) structural change took the form of a relatively larger responsiveness of reserves holdings under fixed rates to a measure of permanent variability in transactions.     

Optimal investment and consumption under a continuous-time cointegration model with exponential utility

In this paper, we study the effects of cointegration on optimal investment and consumption strategies for an investor with exponential utility. A Hamilton-Jacobi-Bellman (HJB) equation is derived first and then solved analytically. Both the optimal investment and consumption strategies are expressed in closed form. A verification theorem is also established to demonstrate that the solution of the HJB equation is indeed the solution of the original optimization problem under an integrability condition. In addition, a simple and sufficient condition is proposed to ensure that the integrability condition is satisfied. Financially, the optimal investment and consumption strategies are decomposed into two parts: the myopic part and the hedging demand caused by cointegration. Discussions on the hedging demand are carried out first, based on analytical formulae. Then numerical results show that ignoring the information about cointegration results in a utility loss.     

Signaling with dividends and share repurchases: a choice between deterministic and stochastic cash disbursements

We study firms signaling with cash disbursements and show thatthe choice of a deterministic or a stochastic disbursement dependson a property of the firm's production function that is analogousto absolute risk aversion for a utility function. With decreasing(increasing) absolute risk aversion, the high-quality firm prefersto distinguish itself from the low-quality firm with a stochastic(deterministic) outlay. We then study in detail two common formsof corporate cash distributions: dividends, a deterministicdisbursement, and share repurchases, a stochastic disbursement.     

新会计准则下寿险公司资产负债管理研究

资产负债管理是影响寿险公司经营成败的重要因素,其长期目标是经济价值最大化.在信息不对称的情况下,会计报表成为寿险公司实施资产负债管理的重要依据和管理内容.我国保险业实施新会计准则后,寿险公司资产与负债的计量方式发生重大变化,会计报表的波动性显著增加,对资产负债管理提出了严峻的挑战.本文研究了新会计准则对传统险、分红险和...     

Optimal capital structure under corporate and personal taxation

In this paper, a model of corporate leverage choice is formulated in which corporate and differential personal taxes exist and supply side adjustments by firms enter into the determination of equilibrium relative prices of debt and equity. The presence of corporate tax shield substitutes for debt such as accounting depreciation, depletion allowances, and investment tax credits is shown to imply a market equilibrium in which each firm has a unique interior optimum leverage decision (with or without leverage-related costs). The optimal leverage model yields a number of interesting predictions regarding cross-sectional and time-series properties of firms' capital structures. Extant evidence bearing on these predictions is examined.     

居民最优消费与投资组合 ——基于不完全市场的分析

运用动态最优控制理论与随机金融分析方法,研究由劳动收入的特质风险与借贷约束导致的非完全市场对消费者最优投资和消费策略、波动及福利损失的影响,得到相应的动态最优投资和消费策略.研究发现:非完全市场会显著抑制消费者的消费动机和投资动机,并加剧消费波动和投资波动.此外,财务困境下非完全市场会对消费者造成高达40％ 的福利损失.