MODEL UNCERTAINTY AND ITS IMPACT ON THE PRICING OF DERIVATIVE INSTRUMENTS

Uncertainty on the choice of an option pricing model can lead to "model risk" in the valuation of portfolios of options. After discussing some properties which a quantitative measure of model uncertainty should verify in order to be useful and relevant in the context of risk management of derivative instruments, we introduce a quantitative framework for measuring model uncertainty in the context of derivative pricing. Two methods are proposed: the first method is based on a coherent risk measure compatible with market prices of derivatives, while the second method is based on a convex risk measure. Our measures of model risk lead to a premium for model uncertainty which is comparable to other risk measures and compatible with observations of market prices of a set of benchmark derivatives. Finally, we discuss some implications for the management of "model risk."     

奈特不确定下资产定价消费模型的建立

在不确定条件下进行资产定价是金融学中的一个重要问题。受金融市场的时变性和人的参与,通常情况下很难得到如收益、利率、波动率等某些变量的精确估计值,现实金融市场中不仅存在概率意义上的不确定性,还存在模糊性,在实际投资中如何对不确定性给出正确的建模就变得非常重要。把不确定性理论引入到传统的资产定价模型中,通过引入不确定性惩罚因子和熵函数建立奈特不确定条件下的最优消费和投资组合模型,能够同时反映随机不确定性和模糊性,可满足投资者的需求。该模型是对经典模型的一种自然推广,它可以适用于不同类型的市场,不同类型的个体,有较好的适用性。     

非期望效用理论研究述评

期望效用理论（EUT）出现后,成为主流经济学和管理学中研究不确定性环境下决策活动的理论基础。但近50年特别是最近20多年来,随着行为科学的发展以及实验经济学的崛起且逐步融入主流,与EUT相抵触的经验证据大量涌现,因此其作为不确定性决策活动的理论根基正在被广泛质疑,各学科寻找EUT替代者的努力催生了多种不同的非期望效用理论。本文在对经典期望效用理论批判的基础上,对国外正处于进展中的非期望效用理论文献进行全面回顾和简单评价,以期为国内从事这一领域理论和应用研究的学者提供一些线索和思路。     

教育质量波动性对住宅价格的影响研究

“学区房热”源于优质教育资源总量不足、学区间教育质量分布不均。通过分离家庭的学区房购置时刻与住房教育价值实现时刻,区分家庭在事前与事后对住宅附加教育收益的不同评估方式,从微观视角分析学区教育质量波动性的不同是导致择校现象和学区房溢价的另一方面原因。为减轻教育质量波动性给义务教育入学环境带来的负面影响,推动绩效公开、持续投入资源、发展一贯制教育是可行的教育调控政策。该发现还可推广于其他具有质量波动性的公共服务,提示在城市建设时应降低这些设施与服务的质量风险,以便从全方位稳定住宅市场价格。     

DISTRIBUTION-INVARIANT RISK MEASURES, INFORMATION, AND DYNAMIC CONSISTENCY

In the first part of the paper, we characterize distribution-invariant risk measures with convex acceptance and rejection sets on the level of distributions. It is shown that these risk measures are closely related to utility-based shortfall risk.
In the second part of the paper, we provide an axiomatic characterization for distribution-invariant dynamic risk measures of terminal payments. We prove a representation theorem and investigate the relation to static risk measures. A key insight of the paper is that dynamic consistency and the notion of "measure convex sets of probability measures" are intimately related. This result implies that under weak conditions dynamically consistent dynamic risk measures can be represented by static utility-based shortfall risk.     

Influence of augmented reality product display on consumers’ product attitudes: A product uncertainty reduction perspective

In the online retail market, consumers' uncertainty about products caused by the physical separation between consumers and products has long been an obstacle. In recent years, online retailers have begun to display their products by using augmented reality technology. However, whether and how the features of augmented reality influence consumers’ product uncertainty remains unclear. In this study, we explore the effects of augmented reality features on product uncertainty reduction and product attitude. The results show that augmented reality can reduce product quality and fit uncertainty by increasing perceived informativeness, sense of presence, and mental imagery. The relationship between augmented reality features and product uncertainty reduction are moderated by product involvement, need for sensory richness and self-brand connection. Ultimately, the reduction of product uncertainty leads to positive product attitude.     

TIME‐CONSISTENT AND MARKET‐CONSISTENT EVALUATIONS

We consider evaluation methods for payoffs with an inherent financial risk as encountered for instance for portfolios held by pension funds and insurance companies. Pricing such payoffs in a way consistent to market prices typically involves combining actuarial techniques with methods from mathematical finance. We propose to extend standard actuarial principles by a new market‐consistent evaluation procedure which we call “two‐step market evaluation.” This procedure preserves the structure of standard evaluation techniques and has many other appealing properties. We give a complete axiomatic characterization for two‐step market evaluations. We show further that in a dynamic setting with continuous stock prices every evaluation which is time‐consistent and market‐consistent is a two‐step market evaluation. We also give characterization results and examples in terms of g‐expectations in a Brownian‐Poisson setting.