一种新型高速数字锁相环的研究

本文针对传统方法实现的数字锁相环(DPLL)工作速率低的问题,通过对一种典型的DPLL的分析,找出影响其工作速率的主要因素,研究并提出了一种全新的高速实现方法,并在实验室进行了数据传输位同步提取实验。     

On optimality in intergenerational risk sharing

Summary. This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante optimality. We show that, at an equilibrium with a productive asset (land) and sequentially complete markets, the intervention of a government may be justified, but only to improve risk sharing between generations. If markets are incomplete, constrained interim optimality is investigated in two-period lived OLG economies. We extend the optimality properties of an equilibrium with land and give conditions under which introducing a pay-as-you-go system at an equilibrium would not lead to any Pareto improvement. Received: October 5, 1998; revised version: April 3, 2001     

税制改革与税收文化滞后分析

本文引入了税收文化滞后的概念,阐明了进行税制改革时将会出现税收文化滞后现象,它将影响到税制结构优化目标的实现,因此必须尽力减弱其影响,以确保税制改革的成效。     

Länger leben — Siechtum und Pflege ohne Grenzen?

At present, our society and its social security system are not prepared to cope with the challenges resulting from the continuous increase of life expectancy. The traditional concept of disease has to be modified for serving the special needs of the elderly. The optimistic compression of disease theory is an intriguing model, but lacks prove by available data. The anti-aging boom diverts the focus from the social and financial burden that will be unevitably caused by long-term care in the future. If there will not be an — up to now unforeseeable — breakthrough in research, particularly dementia will have an enormous impact on social cost which is often underestimated.     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

Explaining the Cross‐Section of Stock Returns in Japan: Factors or Characteristics?

Japanese stock returns are even more closely related to their book-to-market ratios than are their U.S. counterparts, and thus provide a good setting for testing whether the return premia associated with these characteristics arise because the characteristics are proxies for covariance with priced factors. Our tests, which replicate the Daniel and Titman (1997) tests on a Japanese sample, reject the Fama and French (1993) three-factor model, but fail to reject the characteristic model.     

中国城市化的背后--农业的潜在危机

城市化的实质含义是人类进入工业社会时代,社会经济发展速度加快,农业活动的比重逐渐下降、非农业活动的比重逐步上升的发展过程.与这种经济结构的变动相适应,乡村人口比重逐渐降低,城镇人口比重稳步上升,居民的精神面貌和人们的生活方式逐渐向城镇性质转化和强化.2000年中央提出<促进小城镇健康发展的若干意见>,各地掀起"城市化"和"工业化"甚至是"经营城市"的浪潮,致使大量的农业用地转为非农用途,同时产生了大量的失地农民,形成了四千万的失去土地又没有社会保障的农民存在,严重阻碍了城市化的进程.     

Cardinality-based equality of opportunities

We study possible rankings of opportunity profiles. An opportunity profile is a list of opportunity sets, one for each agent in the society. We compare profiles on the basis of the notion of “equality of opportunities”. Our main results show the necessary and sufficient conditions for this comparison to be made using exclusively the information provided by two cardinal measures: the number of common alternatives in all sets of a given profile and the difference between the number of alternatives in the individual sets. We also show that, under additional axioms, we can combine these criteria only in a weighted procedure or in some lexicographic refinements of a weighted procedure.