Boussinesq方程的二阶椭圆余弦驻波解

等深浅水域中的流体运动可由Boussinesq方程描述。众所周知,该方程有行进波解（孤立波及椭圆余弦波）。本文则以Boussinesq方程为控制方程,利用渐近匹配法对椭圆余弦波在直墙上反射进行研究,给出了反射过程中内、外场波形及速度变化的解析表达,从而得到了Boussinesq方程的二阶椭圆余弦驻波型的解析解,并讨论了这类驻波的若干性质。当波长无限增大时,所得解析解收敛于孤立波的情况。这些解析结果不仅有助于揭示岸坡对非线性浅水波影响的力学机理,在海岸防护和开发和岸壁附近结构物的设计条件等工程领域中也具有现实的指导意义。     

The asymptotic distribution of Nagar's bias-adjusted TSLS estimator under partial identification

The asymptotic distribution of the Nagar bias-adjusted two-stage-least-squares estimator is studied under the assumption of partial identification when the number of instruments increases at the same rate as the sample size and the errors are normally distributed.     

ACCOUNTING FOR RISK AVERSION, VESTING, JOB TERMINATION RISK AND MULTIPLE EXERCISES IN VALUATION OF EMPLOYEE STOCK OPTIONS

We present a valuation framework that captures the main characteristics of employee stock options (ESOs), which financial regulations now require to be expensed in firms' accounting statements. The value of these options is much less than Black–Scholes prices for corresponding market-traded options due to the suboptimal exercising strategies of the holders, which arise from risk aversion, trading and hedging constraints, and job termination risk. We analyze the combined effect of all of these factors along with the standard ESO features of multiple exercising rights, and vesting periods. This leads to the study of a chain of nonlinear free-boundary problems of reaction-diffusion type. We find that job termination risk, vesting, finite maturity and non-zero interest rates are significant contributors to the ESO cost. However, we find that in the presence of vesting, the impact of allowing multiple exercise rights on ESO cost is negligible.     

Utility of gambling II: risk,paradoxes, and data

We specialize our results on entropy-modified representations of event-based gambles to representations of probability-based gambles by assuming an implicit event structure underlying the probabilities, and adding assumptions linking the qualitative properties of the former and the latter. Under segregation and under duplex decomposition, we obtain numerical representations consisting of a linear weighted utility term plus a term corresponding to information-theoretical entropies. These representations accommodate the Allais paradox and most of the data due to Birnbaum and associates. A representation of mixed event-and probability-based gambles accommodates the Ellsberg paradox. We suggest possible extensions to handle the data not accommodated.      

多边贷款是否促进了公共投资

自中国恢复世行成员国合法席位以来,多边贷款一直是我国公共投资的重要来源,它占公共投资的比例最高达到27%,平均8.6%,累计金额已达数百亿美元.这些贷款是促进了中国的公共投资水平,还是提高了政府消费,又或者降低了税收,这方面的评价研究很少.本文在宏观经济学的相关理论和模型基础上建立起一套Cowles Commission结构方程组,分别利用1978～2001年的国家和省级两层数据,对上述问题进行了评价.我们的计量分析结果表明,多边贷款并没有促进公共投资的增长,反而降低了税收,提高了政府消费水平.这种影响不同地区是有差异的.总的来看,这种传统意义上的消极影响没有波及私人投资和经济增长.     

A Continuous Time Model to Price Commodity-Based Swing Options

On the commodity market there exist contracts which give the holder multiple opportunities to adjust delivery of the underlying commodity. These contracts are often named “Swing” or “take-or-pay” options. They are especially common on the electricity market.In this paper the price of a Swing option on commodities is investigated under the additional constraint of a recovery time between two different exercise times. We give an explicit characterization of the price function as the value function of a continuous stochastic impulse control problem and prove existence of an optimal control. We investigate the connection between the price function and the solution of a system of quasi-variational inequalities. Finally, we present a numerical algorithm for solving the quasi-variational inequalities, and give some numerical examples.JEL Classification: C61, C62, C63     

我国宏观经济政策与经济波动的实证研究

本文根据Granger因果检验和联立方程模型，利用我国1985—2003年的年度统计数据，对我国宏观经济政策与经济波动之间的关系进行了实证分析。研究结果表明，消费政策、投资政策和外贸政策对经济波动影响的显著性水平要高于财政政策和货币政策对经济波动影响的显著性水平，影响我国经济波动的关键政策并不是财政政策和货币政策，而是消费政策、投资政策和外贸政策。     

Pricing of Forward and Futures Contracts

There has long been substantial interest in understanding the relative pricing of forward and futures contracts. This has led to the development of two standard theories of forward and futures pricing, namely, the Cost-of-Carry and the Risk Premium (or Unbiased Expectations) hypotheses. These studies have modelled the relationship between spot and forward/futures prices either through a no-arbitrage condition or a general equilibrium setting. Relatively few studies in this area have considered the impact of stochastic trends in the data. With the emergence of non-stationarity and cointegration in recent years, more sophisticated models of futures/forward prices have been specified. This paper surveys the significant contributions made to the literature on the pricing of forward/futures contracts, and examines recent empirical studies pertaining to the estimation and testing of univariate and systems models of futures pricing.     

非关税措施量化公式评价

与直接可以用税率高低来度量其保护程度的关税不一样,非关税措施是一种隐蔽的难以直接度量其保护作用的贸易保护主义手段。本文评价了近年来国外普遍采用的非关税措施保护作用的量化方法,包括频度——类型测算法、价格对比测算法、支持率测算法的设计思路和运用状况,以便为不时发生的贸易争端和贸易谈判提供可以用来判断进口国非关税措施保护程度的分析工具。