Mean-variance portfolios using Bayesian vector-autoregressive forcasts

Protfolio optimization is very sensitive to the forecats of returns and (co-)variances of the underlying assets. This paper applies a Bayesian vector-autoregression of the asset universe to predict the returns. Further, the co-variance matrix is forecasted by an Augmented GARCH estimation of the most volatile principle components of the return series. As an empirical illustration, the daily stock returns of the German stocks index DAX have been used to calculate some well-known mean-variance portfolios. Back-testing is used to evaluate the performance. The approach seems to be promising.     

Homelessness as one component of housing instability and its impact on the development of children in poverty

The number of families with children living in poverty and experiencing housing instability and homelessness has increased dramatically over the last two decades. Current public policy decisions will lead to further increases. Understanding the impact of this instability on the emotional, behavioral, and cognitive development of children is imperative. Few studies critically examine the effects of instability on both domiciled and homeless children. This research examined the effects of homelessness and housing instability on 133 children 8 to 12 years of age living in poverty. Results indicate that whether a child is currently homeless is not as significant as overall stability which may have a long ranging effect on a child's future development.     

Das Feuer kleiner Gruppen: Analyse der Entwicklungslogik und -dynamik eines Beratungsprozesses

The spark of small groups: An analysis of the developmental logic and dynamics of a consultancy process In the recent past large group interventions have gained increased attention in the systemic consulting literature. In contrast to this tendency, this paper focuses on the significance and effectiveness of small group interventions in business consultancy.Based on a qualitative analysis of a consultancy process, the effectiveness of small group change processes is documented here: Unlike large groups, small groups not only are far more likely to succeed in developing structures which differ from the existing organizational structures, they moreover are much more likely to develop a strong identity which helps them generate the power necessary for change. Especially in conflict situations and in situations where the pressures that are being put on an organization are increasing, small groups are more likely to maintain their identity, another crucial prerequisite for the initiation of a change process.The paper shows that consultancy systems, which differ in structure from the customer organization, are apt to serve as incubators for the development of strong groups within an organization. These small groups are able to push for organizational changes using conflicts process.     

A multimethod assessment of personal space development in female and male,black and white children

In order to obtain evidence of the effects of demographic parameters and measurement techniques on personal space, several different assessments were used to determine the impact of subject age, race, and sex on interpersonal distancing. Thirteen different variables representing stimulation, paper-and-pencil, and behavioral techniques indicated that as age increased, personal space requirements decreased, particularly for whites. Blacks as compared to whites required less space at age 7, and mixed-sex dyads tended to require more space than same-sex dyads. The results thus indicate that while some previous findings appear to be measurement method specific, others show intermethod consistency.     

Prüfungshonorare in Deutschland – Determinanten und Implikationen

The audit fees available since 2005 as a consequence of the Bilanzrechtsreformgesetz (commercial code reform act) show an extremely high supplier concentration on the German audit market of publicly listed companies. This justifies the assumption of audit fees above perfect market equilibrium prices. However, the complete collection and multivariate regression analysis of all relevant audit fee and client data document a 24 % decrease in audit fees in 2005 and an average 15 % decrease in the two subsequent years due to auditor changes. This can be interpreted as an indicator for price competition. In addition, the audit fee data shows that the audit fee decreases are only partially compensated by subsequent increases. As a consequence, there is no evidence for lowballing at present. Further time series are necessary to show if the current trend is sustainable.     

Waiting time to exhaust lottery numbers

Questions related to lotteries are usually of interest to the public since people think there is a magic formula which will help them to win lottery draws. This note shows how to compute the expected waiting time to observe specific numbers in a sequence of lottery draws and show that surprising facts are expected to occur.