In groupware tools, the activation of a function may affect other userswho might have conflicting interests. We developed technicalmechanisms to support users in resolving them. Contrary to currentimplementations of groupware tools, these mechanisms strengthen theposition of the users who are...

Several portfolio approaches for the purchasing area have been developed in the past. The main reason was to enable companies to follow differentiated sourcing strategies depending on the classification of different purchase items within a defined portfolio. This should enable companies to...

In the standard CAPM with a riskless asset we give a simple proof of existence of equilibria without assuming concavity of the investor's utility functions. Moreover, we give a uniqueness result using assumptions on the risk aversion of investors.

In the standard CAPM with a riskless asset we give a sufficient condition for uniqueness. This condition is a joint restriction on the agents´ endowments and their preferences which is compatible with non-increasing absolute risk aversion and which is inparticular satisfied with constant...

This paper analyzes optimal portfolio choice and consumption with stochastic volatility in incomplete markets.

This paper estimates a trivariate two-factor conditional version of the Intertemporal CAPM of Merton (1973).

This paper shows that preferences alone cannot explain the patterns reported in the literature.

In enhanced annuities, the annuity payment depends on one's state ofhealth at some contracted date while in "standard annuities", it does not.The focus of this paper is on an annuity market where "standard" and en-hanced annuities are oered simultaneously. When all insured know equallywell on...

We present results from the rst large-scale international surveyon risk preferences, conducted in 45 countries. We show substantialcross-country dierences in risk aversion, loss aversion and probabilityweighting. Moreover, risk attitudes in our sample depend not only oneconomic conditions, but...