Working-time reduction and employment: experiences in Europe and economic policy recommendations

The paper seeks to evaluate the evidence on the employment effectsof the collective working-time reductions in Europe over thepast 20 years. While theoretical analyses produce contradictoryassessments, most empirical studies show positive employmenteffects but take insufficient account of these conditions underwhich the reductions in working time were implemented. Theseconditions for the success of collective working-time reductionsinclude an active training policy designed to minimise skillshortages in the labour market, the modernisation of work organisation,wage increases in conjunction with productivity gains and amore equal income distribution.     

A MULTINOMIAL APPROXIMATION FOR AMERICAN OPTION PRICES IN LÉVY PROCESS MODELS

This paper gives a tree-based method for pricing American options in models where the stock price follows a general exponential Lévy process. A multinomial model for approximating the stock price process, which can be viewed as generalizing the binomial model of Cox, Ross, and Rubinstein (1979) for geometric Brownian motion, is developed. Under mild conditions, it is proved that the stock price process and the prices of American-type options on the stock, calculated from the multinomial model, converge to the corresponding prices under the continuous time Lévy process model. Explicit illustrations are given for the variance gamma model and the normal inverse Gaussian process when the option is an American put, but the procedure is applicable to a much wider class of derivatives including some path-dependent options. Our approach overcomes some practical difficulties that have previously been encountered when the Lévy process has infinite activity.     

“气”和“势”的时空化过程——《姜斋诗话》论诗的形象构建

传统诗论探讨诗歌的形象问题,总和某种特定的哲学形态和思想观念密切相连,其构建过程则以营造一种时空间感的方式实现。船山论诗,以此为据而又有所突破。其中,＂气＂是形象在诗中时空化的本体依据,＂势＂是形象时空化的外在特征。如此,于内,是求诗中意之神、理、气的合一;于外,便是求诗之外在空间形态和艺术张力,在＂敛＂与＂纵＂、＂藏＂与＂显＂之间,建构了富于张力的意义空间。     

Continuous time vs. backward induction a new approach to modelling reputation in the finite time horizon context

This paper suggests a new approach to modeling credible reputation in the finite time horizon context, using continuous time and interactions which arrive via a Poisson process. Behavior in the present model does not depend on small ad hoc irrationalities as the end of the horizon nears, and the model preserves the intuitive result that as the end of the horizon nears, the level of reputation declines towards zero. While the current paper considers the predatory pricing case, the approach should also apply whenever reputation and/or cooperation are important.     

基于缩短响应时间的供应链管理系统的实现

系统地研究了基于缩短响应时间的供应链管理模式,提出了四个订单流驱动的控制原理。以缩短供应链响应时间为目标,提出了基于Web的供应链管理系统解决方案。并实现了供应链管理系统的系统管理、客户关系管理、电子购销管理、合同管理、订单管理、仓储管理、运输管理和配送管理功能,该软件系统能够提高管理人员供应链管理的智能化决策水平。     

Ruin Probabilities for Insurance Models Involving Investments

In this paper we study the ruin problem for insurance models that involve investments. Our risk reserve process is an extension of the classical Cramér-Lundberg model, which will contain stochastic interest rates, reserve-dependent expense loading, diffusion perturbed models, and many others as special cases. By introducing a new type of exponential martingale parametrized by a general rate function, we put various Cramér-Lundberg type estimations into a unified framework. We show by examples that many existing Lundberg-type bounds for ruin probabilities can be recovered by appropriately choosing the rate functions.