Minimal Hellinger martingale measures of order <Emphasis Type="Italic">q</Emphasis>

This paper proposes an extension of the minimal Hellinger martingale measure (MHM hereafter) concept to any order q≠1 and to the general semimartingale framework. This extension allows us to provide a unified formulation for many optimal martingale measures, including the minimal martingale measure of Föllmer and Schweizer (here q=2). Under some mild conditions of integrability and the absence of arbitrage, we show the existence of the MHM measure of order q and describe it explicitly in terms of pointwise equations in ? ^d . Applications to the maximization of expected power utility at stopping times are given. We prove that, for an agent to be indifferent with respect to the liquidation time of her assets (which is the market’s exit time, supposed to be a stopping time, not any general random time), she is forced to consider a habit formation utility function instead of the original utility, or equivalently she is forced to consider a time-separable preference with a stochastic discount factor.     

中国通货膨胀预期及其影响因素分析——基于混频无套利Nelson-Siegel利率期限结构扩展模型

综合国债市场的利率期限结构信息以及不同频率的宏观信息,本文构建混频无套利Nelson-Siegel利率期限结构扩展模型,在对不同期限债券进行一致性定价理论约束下,提取了中国通货膨胀预期的期限结构并对其进行影响因素分析。研究结果表明,本文模型提取的通胀预期期限丰富、结果稳健,具有较好的参考价值。通胀预期水平和变动响应主要受货币增长率、通胀率及全球食品价格变动等国内外相关宏观变量的影响,与国债收益率因子之间的关系不显著;国债收益率因子对中长期通胀预期的方差波动具有较强解释力,表明国债定价反映了未来通胀的不确定性。本文研究有助于充分利用我国宏观与金融市场信息条件,有效发现和锚定通胀预期,一方面,研究结果可为政策制定者和市场投资者提供科学的决策参考,另一方面,研究方法对丰富宏观金融领域的分析框架具有参考价值。     

Machine learning for pricing American options in high-dimensional Markovian and non-Markovian models

In this paper we propose two efficient techniques which allow one to compute the price of American basket options. In particular, we consider a basket of assets that follow a multi-dimensional Black–Scholes dynamics. The proposed techniques, called GPR Tree (GRP-Tree) and GPR Exact Integration (GPR-EI), are both based on Machine Learning, exploited together with binomial trees or with a closed form formula for integration. Moreover, these two methods solve the backward dynamic programing problem considering a Bermudan approximation of the American option. On the exercise dates, the value of the option is first computed as the maximum between the exercise value and the continuation value and then approximated by means of Gaussian Process Regression. The two methods mainly differ in the approach used to compute the continuation value: a single step of the binomial tree or integration according to the probability density of the process. Numerical results show that these two methods are accurate and reliable in handling American options on very large baskets of assets. Moreover we also consider the rough Bergomi model, which provides stochastic volatility with memory. Despite that this model is only bidimensional, the whole history of the process impacts on the price, and how to handle all this information is not obvious at all. To this aim, we present how to adapt the GPR-Tree and GPR-EI methods and we focus on pricing American options in this non-Markovian framework.     

通货膨胀与物价目标

针对近年来全国各界对通货膨胀的关切和“物价总水平基本稳定”的提法,本文认为有些认识和思路值得反复理清,包括：如何界定通货膨胀及如何看待通货膨胀;通货膨胀与经济增长如何匹配;中国可能期望的,也是难以避免的通货膨胀率是什么水平。文章提出治理通货膨胀要服从核心任务,应建立现实的通货膨胀观念,并在对保持物价总水平基本稳定的提法进行多视角诠释的基础上,给出了控制物价的几点政策建议。     

寻找理性经济行为的逻辑新起点——试论中国传统伦理下的中庸理性经济人

在主流经济学的视野中,追求效用最大化是社会个体理性行为的基本准则。文章认为主流经济学理性假设的根本问题在于没有揭示特定人类社会的独特复杂特征。主流经济学家忽略了在现实生活中存在于西方文明之外的实然——中庸理性。文章尝试在以中庸理性为假设的理性经济人模型基础上,探讨中国传统伦理下中庸理性经济人的演化及其存在的可能空间。     

我国装备制造业经济效益评价——基于拉开档次法

对现有的工业经济效益评价指标体系进行了分析,并提出了改进建议。运用拉开档次法评价了我国及27个省(自治区、直辖市)装备制造业的经济效益情况。研究结果显示:我国装备制造业的经济效益不容乐观,尤其是西部地区装备制造业的经济效益较低。提出建议:我国装备制造业应调整产业结构,提高自主创新能力,并将经济增长方式由粗放型转变为集约型。     

论经济学的边界

有经济学家认为经济学的基本逻辑可以解释人类所有的行为,他们运用经济行为模式对其他学科的传统“领地”簪越扩张,进行“经济学帝国主义”,试图用经济学的基本分析法方代替所有社会科学。但是随着经济学的扩张,经济学的解释力减弱,扩张的边际收益递减;同时,要求的理论创新加大,即边际成本递增。当两者相等时就达到了一种扩张的均衡,由此可以确立经济学的合理边界。     

深入社会改革,加快建设和谐无锡——无锡“十二五”社会改革途径探讨

经过三十多年的改革开放以后,无锡和全国一样,经济社会有了巨大的发展,但是,社会发展滞后于经济发展的情况仍然存在,急需深入社会改革,推动社会发展。本文在回顾无锡在"十一五"期间社会改革取得的成就基础上,分析了无锡社会发展存在的问题和面临的挑战和机遇,提出了"十二五"期间无锡深化社会改革的目标以及在政府职能转换、社会管理模式创新、实现公共服务均等化和城乡协调发展等四个方面的改革建议,最后提出了保障改革的一些措施。     

Impacts of peer-to-peer accommodation on the hotel industry: Hoteliers’ perspectives

The sharing economy is a new phenomenon that has considerable implications for traditional industries in general and the hospitality sector in particular. Although some recent studies have investigated the effects of sharing economy on the hotel industry, they primarily focused on quantifying its effects which are not exploratory for a phenomenon. This study attempts to achieve two research objectives. First, an exploratory qualitative method via a semi-structured in-depth interview is employed to investigate the impacts of P2P accommodation on the industry from hoteliers’ perspectives in China. Second, the current study provides valuable insights about traditional hotel marketing and operations. A social science perspective is proposed because prior hospitality research, merely in its commercial sense, fails to capture the essence of hospitality. Results indicate that P2P accommodation has effects on the hotel industry in terms of host–guest interactions, product offerings, staff empowerment, and platform collaboration. The study also suggests that the extent to which P2P accommodation impacts the hotel industry is different in terms of hotel star ratings and operating model. P2P accommodation and the hotel industry in China have a supplementary relationship. This study contributes to social studies of the hospitality literature by gaining insights from hotel senior management level. It also has great implications for the hotel marketing and management practices within the sharing context.     

Agriculture–nutrition linkages with heterogeneous,unobserved returns and costs: Insights from Tajikistan

Agriculture–nutrition linkages (ANLs) have been increasingly investigated in the literature. However, nutritional returns and costs of household agricultural production practices (APPs) in semisubsistence settings are poorly understood. We fill these knowledge gaps using pooled cross-section data sets in Tajikistan, where semisubsistence farming and undernutrition coexist despite relatively good agricultural infrastructure and education systems. Agricultural diversification, yield enhancement, production expansion are positively associated with various nutritional outcomes, particularly in areas with poor food market access. Decomposition exercises suggest that nutritional returns and costs of these APPs vary across households, and the adoption of APPs is driven by the expected nutritional returns. In Tajikistan, improving nutrition through household ANLs requires growing the smallholder agricultural sector in multiple dimensions, including diversification, intensification, and expansion, while also understanding better the pathways of ANLs and addressing bottlenecks at appropriate stages of such pathways.