First-time mothers’ birth beliefs,preferences, and actual birth: A longitudinal observational study

Problem

Birth preferences, such as mode and place of birth and other birth options, have important individual and societal implications, yet few studies have investigated the mechanism which predicts a wide range of childbirth options simultaneously.

Pricing power options with a generalized jump diffusion

In this article, the valuation of power option is investigated when the dynamic of the stock price is governed by a generalized jump-diffusion Markov-modulated model. The systematic risk is characterized by the diffusion part, and the non systematic risk is characterized by the pure jump process. The jumps are described by a generalized renewal process with generalized jump amplitude. By introducing NASDAQ Index Model, their risk premium is identified respectively. A risk-neutral measure is identified by employing Esscher transform with two families of parameters, which represent the two parts risk premium. In this article, the non systematic risk premium is considered, based on which the price of power option is studied under the generalized jump-diffusion Markov-modulated model. In the case of a special renewal process with log double exponential jump amplitude, the accurate expressions for the Esscher parameters and the pricing formula are provided. By numerical simulation, the influence of the non systematic risk’s price and the index of the power options on the price of the option is depicted.     

上升敲出期权定价模型的求解方法研究

本文首先阐述了一种新型期权——上升敲出期权的涵义及其模型,提出了一种新的格法对其求解;然后推广到对双重障碍期权的求解;最后给出了实例分析和实证分析,验证了这种新的格法的有效性与快速收敛性。     

亚式期权在依赖时间的参数下的定价

假定标的资产价格模型中的参数为时间t 的函数(即无风险利率r ( t) ,标的资产的期望 收益率μ( t) ,波动率σ( t) 及红利率g ( t) ) ,利用风险中性定价及随机积分的性质,得到连续几 何平均欧式亚式期权在六种情形下价格的解析公式和一个平价关系,且通过调整执行价格的 形式而得到固定执行价格的连续算术平均欧式亚式期权的渐进公式     

Ethical Issues in Continuing Care

No abstract available for this article.     

不确定条件下的IT外包时机选择问题研究

IT外包的业务环境、技术环境和需求的不确定性往往会引起IT服务成本的不确定性。针对IT服务成本的不确定性和IT外包投资的不可逆性,运用传统净现值方法和实物期权方法比较固定价格合同、成本加成定价合同和收益共享合同3种常见合同的外包临界值,分析3种合同下客户企业的等待价值,并讨论客户企业推迟外包情形时的等待时间。研究结果表明,实物期权方法得出的外包临界值高于净现值方法得出的外包临界值;等待价值随无风险利率的增大而减小,随漂移率、变动率的增大而增大;当漂移率与变动率平方的比值大于二分之一时,客户企业选择外包的期望等待时间受无风险利率、漂移率和变动率的影响,其他情形下客户企业的期望等待时间不受无风险利率、漂移率和变动率的影响。研究结论为不确定条件下客户企业外包与否和外包时机的选择提供理论支持和实践指导。     

行政主体义务设定的失衡及价值选择

行政主体义务设定是指行政主体在行政执法的过程中为相对一方当事人确定禁止规则或强加负担的行为 ,它是行政权的延伸。与其它类型的行政权行使一样 ,义务设定必须符合法定条件 ,同时又要符合行政合理原则 ,这也是行政法治、依法行政的要求。然而 ,行政法治实践中行政主体义务设定的失衡现象非常普遍 ,如对程序负责不对实体负责的失衡 ,以经济利益为重而以社会利益为轻的失衡等。因此 ,必须探讨义务设定中的合理价值选择 ,即有利于建立法律秩序、有利于实现公民权、有利于行政管理过程有效实现、充分体现行政伦理准则等四个方面的价值选择。     

东亚模式的理论分歧与现实发展

东亚模式是一种现实存在,是东亚地区在实现现代化过程中体现出来的共同特质,它在东亚经济的起飞和发展中起了导向作用。但理论界对东亚模式有不同的评价,我们认为应该从理论和现实的比较中分析东亚模式的本质和价值。     

一种混合建模方法及其在ETF期权定价中的应用

科学合理的交易型开放式指数基金(ETF)期权定价有利于充分发挥其风险对冲功能,也是一个需要准确掌握市场规律并兼顾经济学意义的复杂建模过程。本文提出了一种新的混合建模方法,将嵌套长短时记忆神经网络模型(NLSTM)与Heston模型结合,实现ETF期权定价偏差的动态修正,并基于华夏上证50ETF、嘉实沪深300ETF和华泰柏瑞沪深300ETF的高频期权数据,实验验证了所提方法的有效性。研究结果表明,不同类型ETF期权价格的波动特征差异显著,无论是基于BS定价模型还是Heston定价模型都难以准确刻画ETF期权价格的复杂变化规律。通过将NLSTM神经网络模型与Heston模型结合,能够有效地捕捉不同类型ETF期权的动态变化规律,从而提升ETF期权定价的准确性。     

Transfer of risk in the newsvendor model with discrete demand

In this paper we consider the transfer of risk in a newsvendor model with discrete demand. We view the newsvendor model as a leader/follower problem where the manufacturer (leader) decides the wholesale price and the retailer (follower) decides the quantity ordered. Taking a Pareto-optimal contract as a starting point, the manufacturer wishes to design a real option contract to enhance profits. A new real option contract is said to be feasible if both parties' expected profit is at least as great as in the original contract. When demand is discrete, there are usually infinite feasible contracts that yield maximum expected profits to the manufacturer. In the paper we show that either all, some or none of these real option contracts offer an improved position for the retailer.