Time diversification and security preferences: A stochastic dominance analysis

We use stochastic dominance to test whether investor should prefer riskier securities as the investment horizon lengthens. Return distributions for stocks, bonds, and U.S. Treasury bills are generated for holding periods of one to 25 years by simulation. For each holding period, stochastic dominance tests are run to establish preferences between the alternative security classes. Contrary to previous mean-variance based studies, we find no evidence that high-risk securities (stocks) dominate low-risk securities (bonds, Treasury bills) as the investment horizon lengthens. However, we do find that corporate bonds systematically dominate government bonds.     

Optimal portfolio choice in the bond market

We consider the Merton problem of optimal portfolio choice when the traded instruments are the set of zero-coupon bonds. Working within a Markovian Heath–Jarrow–Morton model of the interest rate term structure driven by an infinite-dimensional Wiener process, we give sufficient conditions for the existence and uniqueness of an optimal trading strategy. When there is uniqueness, we provide a characterization of the optimal portfolio as a sum of mutual funds. Furthermore, we show that a Gauss–Markov random field model proposed by Kennedy [Math. Financ. 4, 247–258(1994)] can be treated in this framework, and explicitly calculate the optimal portfolio. We show that the optimal portfolio in this case can be identified with the discontinuities of a certain function of the market parameters.     

Measuring Inflation Expectations Uncertainty Using High‐Frequency Data

Inflation expectations play a key role in determining future economic outcomes. The associated uncertainty provides a direct gauge of how well‐anchored the inflation expectations are. We construct a model‐based measure of inflation expectations uncertainty by augmenting a standard unobserved components model of inflation with information from noisy and possibly biased measures of inflation expectations obtained from financial markets. This new model‐based measure of inflation expectations uncertainty is more accurately estimated and can provide valuable information for policymakers. Using U.S. data, we find significant changes in inflation expectations uncertainty during the Great Recession.     

Machine learning in individual claims reserving

Machine learning techniques make it feasible to calculate claims reserves on individual claims data. This paper illustrates how these techniques can be used by providing an explicit example in individual claims reserving.     

Automatic balancing mechanisms for notional defined contribution accounts in the presence of uncertainty

The notional defined contribution model combines pay-as-you-go financing and a defined contribution pension formula. This paper aims to demonstrate the extent to which liquidity and solvency indicators are affected by fluctuations in economic and demographic conditions and to explore the introduction of an automatic balancing mechanism (ABM) into the pension scheme. We demonstrate that the introduction of an ABM reduces the volatility of the buffer fund and that, in most cases, the automatic mechanism that re-establishes solvency produces the highest value of the risk-adjusted notional factor.     

Expected exponential utility maximization of insurers with a Linear Gaussian stochastic factor model

In this paper, we consider the problem of optimal investment by an insurer. The wealth of the insurer is described by a Cramér–Lundberg process. The insurer invests in a market consisting of a bank account and m risky assets. The mean returns and volatilities of the risky assets depend linearly on economic factors that are formulated as the solutions of linear stochastic differential equations. Moreover, the insurer preferences are exponential. With this setting, a Hamilton–Jacobi–Bellman equation that is derived via a dynamic programming approach has an explicit solution found by solving the matrix Riccati equation. Hence, the optimal strategy can be constructed explicitly. Finally, we present some numerical results related to the value function and the ruin probability using the optimal strategy.     

保险公司市场风险经济资本度量研究

经济资本(EC)是在既定期间和置信水平下,公司根据实际承担的风险计算的用以吸收非预期损失的资本额度,目前市场风险是整体经济资本测算体系中最为突出的风险.根据当前保险运营与资产投资的比例特征,同时对资产端与负债端建立市场风险投资模型,采用嵌套随机模拟方法进行两阶段情景生成,度量未来一年内不同风险测度下的市场风险经济资本需求,并对比不同情景数量下的测算稳定性.结果证明:随着内部或外部情景模拟次数的增加,市场风险经济资本测算结果对于极端风险的预测趋于稳定,在内外部情景数量乘积相同时运算时间基本一致.当内外部两阶段情景生成参数差异较大的情形下,应适当增加情景生成数量,以确保对于极端风险预测的准确性.     

Role of formal standards in transition to the technology frontier: Korean ICT systems

According to traditional wisdom, latecomer countries improve their technological capabilities in reverse of the product cycle, that is from mature towards new technologies. However, improvement of standards capabilities in this process has not been revealed clearly. This paper confirms similar patterns for improving formal standards capabilities as for the technological capabilities, but records some possible differences in the rate of catch-up when latecomers approach the technology frontier; a forward moving position where technology leaders (typically advanced countries) develop or conceptualize new technologies before being turned into products or systems. A number of case studies of South Korean ICT systems reveal that transition to the technological frontier is increasingly related to how they target and carry out formal standardization. The common elements driving differences in rates of successful catch-up for ICT systems standards are not only limited to generic standards capabilities, but also rely on characteristics of technology trajectories, national strategic focus, and organizing for standardization.³ This implies that a nation should not be discouraged by slow progress in standards-setting during earlier stages. Once a minimum level of capabilities is achieved, a nation pro-active in standards from the beginning may attain higher rates of catch-up near the technology frontier.     

非封闭的SIS确定模型与随机模型的研究

文章通过对具常数输入人口,死亡率和出生率的的SIS模型的确定形式与随机形式的研究,得到文中定义的基本再生数R0燮1时,传染病最终会消失,而当基本再生数大于等1时,传染病人数将稳定,传染病最终会形成地方病,最后验证了两种模型的结果是一致的。     

森林资源资产组合随机控制模型及决策

在界定了森林生态资产与森林资源资产组合概念的基础上,构建和模拟了基于随机控制理论的森林资源资产组合模型,为森林经营管理者提出了相应的结论和建议:森林经营管理者可以根据最优采伐量与木材价格、补偿价格、成本系数、税率、贴现率、生长率等参数之间的关系,获得在市场经济变动条件下的最优森林资产组合,以保证森林资产净收益的稳定增长。