Optimal reinsurance and dividend for a diffusion model with capital injection: Variance premium principle

This paper considers the optimal dividend problem with proportional reinsurance and capital injection for a large insurance portfolio. In particular, the reinsurance premium is assumed to be calculated via the variance principle instead of the expected value principle. Our objective is to maximize the expectation of the discounted dividend payments minus the discounted costs of capital injection. This optimization problem is studied in four cases depending on whether capital injection is allowed and whether there exist restrictions on dividend policies. In all cases, closed-form expressions for the value function and optimal dividend and reinsurance policies are obtained. From the results, we see that the optimal dividend distribution policy is of threshold type with a constant barrier, and that the optimal ceded proportion of risk exponentially decreases with the initial surplus and remains constant when the initial surplus exceeds the dividend barrier. Furthermore, we show that the optimization problem without capital injection is the limiting case of the one with capital injection when the proportional transaction cost goes to infinity.     

Optimal Controls for a Large Insurance Under a CEV Model: Based on the Legendre Transform-Dual Method

The purpose of this paper is to consider the optimal proportional reinsurance and investment strategies for an insurance company. The insurer’s surplus process is approximated by a Brownian motion with drift. The insurance company can purchase proportional reinsurance and invest the surplus in a financial market which includes one risk-free asset and one risky asset whose price is modeled by a CEV model. The primary problem is changed to the dual problem by implying Legendre transform. When the objective of the insurance company is to maximize the expected logarithmic utility from terminal wealth, the closed-form expressions for the optimal reinsurance-investment policy which is different to the Merton case to the primal optimal problem are obtained and numerical simulations are provided to demonstrate our results. Moreover, we find an interesting result that risk exposure is non-monotonic in the cost of reinsurance.

     

科技保险基金风险管理与投资策略研究展望

在介绍科技保险与再保险研究情况的基础上,探讨如何针对科技保险的风险机制和保险特征研究科技保险基金的风险管理与投资策略问题。在综述相关研究现状与趋势后认为,可从以下方面展开：建立风险资产模型,构造一个新型风险函数,研究最优再保险策略与各参数之间的关系以及最优分红策略,并研究风险资产模型对破产概率和确定时刻预期累计收益的影响;研究再保险方式对破产概率和确定时刻预期累计收益的影响;研究不同效用函数对不同确定时刻预期累计收益的影响,并引入不同风险测度方法,研究在不同情形下如何选择最优风险测度准则;考虑再保险双方,设计一种新的保险机制;建立试点平台,采集大量经验概率,并以此为基础建立科技保险的费率厘定模型,进而形成一套方法体系。     

Optimal risk and dividend control problem with fixed costs and salvage value: Variance premium principle

In this paper we study the combined optimal dividend, capital injection and reinsurance problems in a dynamic setting. The reinsurance premium is assumed to be calculated via the variance principle instead of the expected value principle. The proportional and fixed transaction costs and the salvage value at bankruptcy are included in the model. In both cases of unrestricted dividend rate and restricted dividend rate, we obtain the closed-form solutions of the value function and the optimal joint strategies, which depend on the transaction costs and the profitability in future.     

股权集中度视角下高管团队特征对现金股利政策的影响

现金股利政策是上市公司对盈利进行分配或留存用于再投资的决策问题,在公司经营中起着至关重要的作用。探究了高管团队特征(规模、年龄、性别、学历背景)对企业现金股利政策的影响,研究发现管理团队的规模越大、平均年龄越大,企业现金股利支付率越高,表明企业管理团队人数越多,年龄越大,越容易采用较高的股利支付率,而管理团队的平均学历越高,越倾向于选择较低的现金股利分配率。说明更高学历的管理层认为,较低的现金股利支付水平才是有利于企业发展的股利支付水平。男性管理层和女性管理者对企业支付现金股利的高低并没有明显的差异。进一步研究发现,企业的股权越集中,管理者的特征对现金股利政策的影响会被弱化。也就是说,股权集中度会显著削弱管理者特征对公司现金股利政策的影响,该实证结果也印证了上市公司中代理问题的普遍存在。研究结果可为企业管理团队的合理配置提出可以借鉴的依据以及实证结果的支持。     

Present bias and corporate tax policies

Two major forms of corporate tax policies are dividend and profits taxes. Based on conventional corporate theory, these tax policies distort the firm's investment decisions and decrease firm value. However, this paper shows that under hyperbolically discounted preferences, dividend taxation is capable of boosting firm investment in a value‐enhancing way. The hyperbolically discounted present value can be interpreted as reflecting irrational myopic preferences or, as we demonstrate, reduced‐form implications of corporate agency issues. Both cases result in an underinvestment problem for the firm, but the firm valuation criteria differ. The optimal taxation issue is discussed under a Cobb–Douglas production function setting.     

Regulated absolute ruin problem with interest structure and linear dividend barrier

The uncontrolled surplus of an insurance company is a classical risk model. Now the risk model includes three features, namely debit interest, short-term and long-term invested interest, and linear dividend barrier. In this paper, the PDMP method and martingales are used for solvency studies in the risk model under regulation of minimum cash requirement. The integro-differential equations are derived for the expected discounted dividends under absolute ruin. In the case of exponential claim amounts, explicit expressions are obtained, as well as the numerical illustrations and their economic interpretation.     

Dynamic asset allocation with ambiguous return predictability

We study an investor's optimal consumption and portfolio choice problem when he is confronted with two possibly misspecified submodels of stock returns: one with IID returns and the other with predictability. We adopt a generalized recursive ambiguity model to accommodate the investor's aversion to model uncertainty. The investor deals with specification doubts by slanting his beliefs about submodels of returns pessimistically, causing his investment strategy to be more conservative than the Bayesian strategy. Unlike in the Bayesian framework, the hedging demand against model uncertainty may cause the investor's stock allocation to decrease sharply given a small doubt of return predictability, even though the expected return according to the VAR model is large. Over much of the parameter space, the robust strategy is very close to the Bayesian strategy with Epstein–Zin preferences and risk aversion chosen to match the same average portfolio holdings. This is true in particular when the IID model is unlikely and the dividend yield is low, as in recent years. However, differences in strategies can be substantial if the IID model is unlikely and the dividend yield is high.     

Internal rationality, imperfect market knowledge and asset prices

We present a decision theoretic framework in which agents are learning about market behavior and that provides microfoundations for models of adaptive learning. Agents are ‘internally rational’, i.e., maximize discounted expected utility under uncertainty given dynamically consistent subjective beliefs about the future, but agents may not be ‘externally rational’, i.e., may not know the true stochastic process for payoff relevant variables beyond their control. This includes future market outcomes and fundamentals. We apply this approach to a simple asset pricing model and show that the equilibrium stock price is then determined by investors? expectations of the price and dividend in the next period, rather than by expectations of the discounted sum of dividends. As a result, learning about price behavior affects market outcomes, while learning about the discounted sum of dividends is irrelevant for equilibrium prices. Stock prices equal the discounted sum of dividends only after making very strong assumptions about agents? market knowledge.     

Optimal reinsurance policies with two reinsurers in continuous time

An optimal reinsurance problem of an insurer is studied in a continuous-time model, where insurance risk is partly transferred to two reinsurers, one adopting the expected-value premium principle and another one using the variance premium principle. The insurer aims to select an optimal reinsurance arrangement to minimize the probability of ruin. To provide an easy-to-implement solution to the problem, (semi)-explicit expressions for the optimal reinsurance strategies as well as the minimal ruin probabilities are derived for several claims distributions. Numerical studies including a real-data example based on the Danish fire insurance losses are provided to illustrate the solution of the problem. Our empirical results based on the Danish data reveal that the heavy-right-tailedness of claims distributions has a significant impact on the optimal reinsurance strategies and has a quite pronounced impact on the residual risk described by the minimal ruin probability.     

Estimates for the optimal control policy in the presence of regulations and heavy tails

We consider a classical heavy tailed risk model, included in a regulation mechanism. The regulator exercises a minimal cash requirement level and penalties for violating it to regulate the insurance firm. The problem of the insurance firm is to establish an investment and risk exposure policy as well as a barrier dividend strategy, which is a function of the strategy used by the regulator. For regularly varying tailed claim size distributions, we find the asymptotics of the stationary distribution of the risk model and derive fundamental asymptotic results of the insurance firm's problem. In the special case of Pareto claim size distributions, the asymptotic optimal control policy is found in closed form, as well as numerical results.     

Dividend Variability and Stock Market Swings

This paper examines the extent to which swings in stock prices can be related to variations in the discounted value of expected future dividends when investors face uncertainty about their future behaviour. I develop an econometric model that accounts for the instability of U.S. dividend growth and discount rates during the past 120 years. Estimates of the model reveal that changing forecasts of future dividend growth account for more than 90% of the predictable variations in dividend-prices. The estimates also imply that instability in the dividend and discount rate processes contribute significantly to the predictability of long-horizon stock returns.     

Financial characteristics of Australian initial public offerings from 1994 to 1999

A variety of financial characteristics of Australian initial public offerings (IPOs) for the period 1994–1999 are explored. A number of previous Australian studies have investigated the initial day underpricing and longer term underperformance of IPOs and this study updates those papers. This paper partitions the IPO data into no liability/limited liability; share option/no share option; underwriter option/no underwriter option and dividend reinvestment/no dividend reinvestment characteristics to better understand the types of IPOs that list on the Australian Stock Exchange. The data supports the findings of previous studies in that IPOs are underpriced at the time of listing and underperform the market in the first year following their listing.     

Profit Maximization and the Market Selection Hypothesis

We examine the proposition that competitive firms must behave as if they were maximizing profits; otherwise they would go bankrupt, or even fail to be financed in a competitive capital market. We investigate a model in which an entrepreneur raises funds for a risky enterprise on a competitive capital market, by offering a "dividend policy" based on the realized (stochastic) flow of earnings. We show that an entrepreneur who maximizes the expected sum of discounted dividends is sure to fail in finite time. On the other hand, many other behaviours yield positive expected profits and are able to attract investment funds, and yet result in a positive probability of surviving forever. As a consequence, if new firms have sufficiently diverse behaviours, then even if there is a constant stream of new entrants, after a long time practically all of the surviving firms will not have been maximizing profits.     

会计信息披露质量与股东忠诚度关系——基于深市上市公司的实证研究

投资者关系管理可以提高公司可信度,进而提高投资者满意度和忠诚度,而提高信息披露质量可以提高公司可信度。那么,在投资者关系管理的前提下会计信息披露质量能否最终带来股东忠诚度呢?文章运用实证分析法,以2004-2005年在深圳交易所发行并上市的A股上市公司作为样本,对上市公司会计信息披露质量与股东忠诚度之间的关系进行统计检验。研究发现,会计信息披露质量与前十大流通股股东增持率有显著的正相关关系,即会计信息披露质量的提高会增加股东忠诚度。研究结果也表明深市信息披露考核等级每增加10%,前十大流通股股东的增持率就会增加大约2%。同时发现,股本扩张能力越强,流通股股东增持率越大,越能吸引股东并提高股东忠诚度。但是,公司盈利能力、公司成长性、公司治理结构和公司规模对增强前十大流通股股东的增持率无显著作用。     

利益与风险偏好差异:上市公司委托理财行为及对策的经济学分析

通过对上市公司决策主体分企业和个人两个层次的分析发现由于企业的内部控制者在委托理财行为中可以获得较大收益却无需承担失败的损失,加上长期的执法不力,他们与企业存在利益与风险偏好上的差异,从而解释了那么多的上市公司对风险很大的委托理财趋之若鹜的原因.要重构上市公司委托理财行为中的"共有信念",需要加大执法力度,且实现一定约束下的法律成本在用于制定新的法规和执行已有法规之间的优化配置;此外,通过提高企业控制人的分成比例,设立企业控制人的个人保证账户也可以减少企业控制人在委托理财中的违法违规行为.     

媒体关注与公司现金股利支付*

随着中国证监会针对上市公司现金股利支付行为的一系列政策的出台,公司的现金股利支付行为成为广受热议的重点话题。本文从媒体关注视角研究了中国上市公司的现金股利支付行为。通过实证研究,本文得到如下研究结论：（1）媒体关注的增多可以显著提高公司未来股利支付意愿和支付水平;（2）媒体关注与“铁公鸡”公司、“微股利”公司的比例显著负相关;（3）与国有控股公司相比,媒体关注对民营控股公司未来股利支付意愿和支付水平的正面影响更为显著;（4）媒体关注对第一类和第二类代理问题更严重的公司的现金股利支付意愿和支付水平的正向影响更强。进一步的研究还显示,媒体关注与现金股利支付意愿和支付水平的正相关关系在管理层持股比例低、非国际四大会计师事务所审计、分析师跟踪少的公司样本中更显著。以上结论说明媒体关注是除行政治理外,另外一种督促上市公司支付现金股利的重要机制。本文除了具有丰富媒体治理和股利政策两方面理论研究的贡献外,对监管机构规范资本市场股利支付行为和保护投资者权益具有重要政策启示。     

On income fluctuations and capital gains

We consider the infinite time horizon problem of asymptotically maximizing the expected accumulated discounted utility in a one-good production economy. The available capital in a given period is given by the production of the previous period plus a random variable. The product of the discount and interest factors is either (1) greater than or (2) equal to one. Under (1) the optimal policy exists under certain conditions and always under (2). The optimal capital sequence almost surely goes to infinity. Under (1) with conditions on the utility one almost surely reaches a capital level above which the sequence is increasing.     

The effect of ceded reinsurance on solvency of primary insurers

Primary insurance companies diversify their underwriting risk and thus improve their financial stability through buying reinsurance contracts. However, excessive use of reinsurance by an insurance company may signal the presence of financial difficulties. In fact, as research shows, a less solvent insurer tends to use more reinsurance because of its inability to raise needed capital in the financial market. Thus, regulators need to pay extra attention to insurers that overly use reinsurance since such behavior could signal an insurer's disproportionately high risk and its eventual probability of insolvency.     

企业采用新技术的时点博弈分析

技术创新可以为企业带来超额利润，具有极大的经济价值，然而新技术的不确定性和风险性又使得企业不会立即采用。本文通过构建双寡头垄断博弈模型对企业采用新技术的时点进行研究，证明企业采用新技术时存在一个最佳时点，在这个最佳时点之前，企业应采取等待策略。