In spite of the widespread use of the concept of potential output in economic theory and empirical applications as well as in economic policy debates, the historical background and the assumptions inherent to this concept are rarely made transparent, let alone critically questioned. Against this background this book sets out to determine the extent to which the concept of potential output rests on clearly defined theoretical foundations and how far prevailing empirical quantification methods really provide reliable insights into potential output growth of an economy. In addition, the authors examine alternative methods for a forward-looking assessment of potential output growth.

Looking back over the last decade it can be said with some justification that sig nificant progress has been achieved on the way towards fully integrated financial markets in Europe. The 1993 Internal Market initiative and the Euro introduction in 1999/2002 constitute important milestones. The integration process has further been intensified by market developments like the surge in mergers and acquisi tions and by technological innovations like internet based distribution. As a result, some market segments today do no longer have a national character. Nevertheless, this success should not obscure the fact that integration of financial services markets is still a long way from the level of integration that exists within national markets. Particularly for retail financial services national borders still constitute a considerable de facto barrier. The absence of frequent direct cross border links between financial service providers and retail consumers holds true despite the fact that the Euro has made product comparisons easier and that the internet has reduced information costs to a considerable extent."

The general review of the European Union's budget scheduled for the years 2008 and 2009 offers a unique opportunity for reflections. Explicitly this review is "without taboos" so that also substantive changes can and should be debated. Without doubt much better budgetary systems can be imagined compared to the status quo of the EU budget which is the outcome of a path-dependent process and where many details are only understandable by taking account of the historical context of past decisions. However, even if much better systems could be designed in theory, each reform suggestion, in the end, must pass the reality check of fi- ing unanimous support from all 27 member countries. This restriction heavily l- its the universe of available reform options. Faced with that difficulty the ZEW project team embarked on the adventure to think about possible reform options for the future EU own resource system. This volume documents the conclusions. At first sight our reform suggestion may - pear to be of a rather piecemeal nature since we recommend a reform model with strong ties to the status quo. Nevertheless, we are convinced that our seemingly minor changes will set the budget on a path towards a more rational European budget which, in the end, will create leeway for financing European policies with a true European value added. We gratefully acknowledge financial support from the German Federal Min- try of Finance in conducting this study.