Diagnosis and therapy of male gamblers in a university psychiatric hospital

From 1980 to mid-1990 fifty-one gamblers were evaluated and treated at the psychiatric university hospital of Homburg/Saar in Germany. All were men with a mean age of 33.7 years. Gambling had lasted 5.2 years on average. Most patients were motivated to undergo therapy by members of their family. The majority of them had been in psychotherapeutic treatment before. Thirty-six of the 51 patients had committed punishable acts including fraud and embezzlement and, in 7 cases, robbery. The sample could be divided into three clinical subgroups. The first group consisted of patients with severe psychiatric diseases such as schizophrenia, manic-depressive illness or organic brain disorder. Patients of the second group suffered from serious personality disorders. Those of the third group showed deep-rooted problems in their current relationships.This article is an extension of the special issue on Gambling in Europe edited by Iver Hand, M.D.     

Public pensions in transition

The main purpose of this paper is to analyze problems of financing an old-age insurance when birth rates are low and population declines or fertility fluctuates with time. A government then searches for optimal policies to cope with such problems. A first criterion could be seen in the Pareto principle. But we all know that there is no way out of PAYG unless at least one generation has to pay for the transition. Therefore an optimal policy is concerned with intergenerational redistribution and optimal growth.In the absence of public pensions the economy will in the long run converge to a steady state which is not optimal in the sense of a golden rule. This dynamic in-efficiency results from the decentralized decision making by the consumers and the firms. If the PAYG system influences the savings ratio of the economy, public pensions can be seen as an instrument to implement a modified golden rule.Paper presented at the ISPE-conference on The Fiscal Implications of an Ageing Population, Vaalsbroek, The Netherlands, May 30–June 1, 1990. I am obliged to Dieter Bös, Friedrich Breyer, Christian Keuschnigg, Wolfgang Kitterer, and an anonymous referee for helpful comments on an earlier draft of this paper. Financial support through Deutsche Forschungsgemeinschaft, SFB 303 is gratefully acknowledged.     

Comparison of different estimation techniques for portfolio selection

The main problem in applying the mean-variance portfolio selection consists of the fact that the first two moments of the asset returns are unknown. In practice the optimal portfolio weights have to be estimated. This is usually done by replacing the moments by the classical unbiased sample estimators. We provide a comparison of the exact and the asymptotic distributions of the estimated portfolio weights as well as a sensitivity analysis to shifts in the moments of the asset returns. Furthermore we consider several types of shrinkage estimators for the moments. The corresponding estimators of the portfolio weights are compared with each other and with the portfolio weights based on the sample estimators of the moments. We show how the uncertainty about the portfolio weights can be introduced into the performance measurement of trading strategies. The methodology explains the bad out-of-sample performance of the classical Markowitz procedures.     

Rank tests in the two-sample scale problem with unequal and unknown locations

The two-sample scale problem is studied in the case of unequal and unknown location parameters. The method proposed is based on the idea of Moses (1963) and it is distribution-free. The two samples are separated into random subgroups of the same sizek. It is proposed to choosek=4 and to apply the Wilconxon test or the Savage test to the ranges or sample variances of the subgroups. The asymptotic power functions of the tests are compared. For small and moderate sample sizes simulations are carried out. Relations to some other procedures, especially to the method of Compagnone and Denker (1996) are briefly discussed.     

温哥华公交线网和运营规划模型及启示

温哥华作为公交系统非常完善和发达的城市,由TransLink负责地区公交规划运营、管理和融资,以及区域公交模型(RTM)的开发和应用.从模型产生的背景、模型构架和要素以及模型的标定进行阐述,并举例说明模型在温哥华城市公交规划项目中的具体应用,旨在为中国公共交通线网和运营模型的建立提供可借鉴的经验.