Unification fundamentally changed the terms of quantitative macroeconomic analysis for Germany. Two main areas concerned are data availability for the eastern part of Germany and structural changes within the behavioural equations after unification. Our paper presents results from the estimation...

A combinatorical problem is said to be of high computational complexity, if it can be shown that every efficient algorithm needs a high amount of resources as measured in Computing time or storage capacity. This paper will (1) introduce some basic concepts of mathematical complexity theory; (2)...

In econometric modelling the choice of relevant variables is of crucial importance for the Interpretation of the results. In many cases it is based on some a priori knowledge from economic theory and a rather heuristic procedure for determining other influential variables sometimes based on an...

Aggregation may be harmful but cannot always be avoided in the analysis of complex econometric models. It should be carried out intelligently by choosing ein aggregative model optimally for modes of aggregation speeified in advance, i.e. minimizing the bias introduced by aggregation and...

Over the last decade credit rationing has been regarded increasingly as the outcome of asymmetric Information. Profit maximization of the banks might lead to interest rates lower than the market equilibrium rate. Administering loans at a higher interest rate to the rationed customers will...

Asymmetric information between lender and borrower is made responsible for financing constraints at the firm level which may influence real activity. In this paper a standard model of credit rationing due to adverse selection and adverse incentive effects is used to derive hypotheses on causes...

A widely used method in the analysis of complex econometric models is to replace the "true model" by a highly simplified aggregative one in which the variables are grouped and replaced by sums or weighted averages of the variables in each group. The analysis of the problem of choosing an...

Mengenrationierungsmodelle erwiesen sich in den vergangenen Jahren als geeignete Instrumente, um Entwicklungen auf Güter- und Arbeitsmärkten zu beschreiben. Wesentliches Ingrediens dieser Modelle ist die Abkehr von der Annahme ständig preisgeräumter Märkte. Als Ursache für die Rationierung...

A widely used method in the analysis of complex econometric models is to replace the "true model" by an aggregative one in which the variables are grouped and replaced by sums or weighted averages of the variables in each group. The analysis of the problem of choosing an aggregative model...