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     

银企关系与会计信息稳健性——中国资本市场的经验证据

本文以Watts（2003）的契约理论为基础，分析股东与债权人之间利益冲突对会计信息稳健性的影响。虽然会计信息稳健性有助于保护债权人的利益，但是如果股东可以作为公司的债权人，则投资者对会计信息稳健性的需求下降。本文采用Basu（1997）模型分析了2004年中国上市公司会计信息稳健性，发现国家控制的上市公司的会计信息稳健性程度较低，而民营控制的上市公司会计信息稳健性程度较高，但是股东特征对会计信息稳健性的影响，随着银行在公司中利益的增加而趋于一致。     

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.