Under fairly weak conditions it is shown that an optimal portfolio choice exists and is unique. It is further shown that this choice is a continuous function of the joint distribution function of the random returns on the assets from which the choice is made.

Within the framework of a microeconomic model of leisure demand, the determinants of German tourists' decisions whether to spend vacation at all, which activities to pursue, and which travel destination to choose are investigated empirically. Three-stage nested multinomial logit models are...

The paper analyses German import sof green coffee using both descriptive statistical and econometric tools. As determinants of import demand we consider not only prices and income but also the structure of the German market of roasted coffee and two institutional arrangements which had...

An adequate stochastic model for shares as dependent variables is provided by the Dirichlet distribution. The paper considers two different parametrizations which lead to linear and nonlinear Dirichlet share equations. Using an inequality for the trigamma function the global concavity of the...

Discrete choice models and qualitative response models are intimately related. Usually both are based on a logistic specification. In many applications the two approaches have been combined leading to a 'discrete choice model including socio-economic explanatory variables'. The paper desdribes...

The paper reports on an attempt to analyse individual travelling behaviour by discrete choice models. It shows that among the socio-economic variables 'income (of household)' is the variable which influences the decision whether a trip is taken at all whereas 'age' seems to be the most important...

Share equations play an important role in applied economic research, notably in marketing and demand analysis. Both market shares and budget shares have been used as dependent variables in econometric models which were partly motivated by microeconomic theory. However attempts of econometricians...