Results from portfolio models for credit risk tell us that loan concentration in certain industry sectors can substantially increase the value-at-risk (VaR). The purpose of this paper is to analyze whether a tractable "infection model" can provide a meaningful estimate of the impact of...

Since the early 1990s an unprecedented process of consolidation has taken place in the banking sector in most industrialised countries raising concern of policymakers that it may reduce access to credit for the small business sector. While most of the existing empirical studies have focused on...

Eine Welle von Fusionen hat die Weltwirtschaft erfasst. Allein die Dimension der bei Großfusionen genannten Summen, die nicht selten das Bruttoinlandsprodukt von Volkswirtschaften übersteigen, führen zu einem erheblichen Maß an Verunsicherung. Dies wird auch in den Überschriften von...

Substantial increases in retail concentration (particularly in Europe) raise concerns about the welfare implications for consumers. In a formal model, we argue that retailer market power reduces upstream firms incentives to introduce new products. On the basis of a survey of firms in German food...

The last couple of decades have seen an increased retail concentration around the world, particularly in Europe. Views on the welfare implications of this severe change are controversial. Consumers might benefit because larger stores (owned by larger retailer chains) offer more product choices....

Theory predicts a positive relationship between market concentration and profitability in most scenarios. In empirical work, however, this relation is frequently not found or only a weak connection is observed. We compare the performance of concentration and market share variables, which are...

We examine the bipartite graphs of German corporate boards in 1993, 1999 and 2005, and identify cores of directors who are highly central in the entire network while being densely connected among themselves. Germany's corporate governance has experienced significant changes during this time, and...

This paper explores the impact of R&D subsidies on the concentration of R&D in an economy. First, governments are often criticized of subsidizing predominantly larger firms and thus contribute to persistence of leadership in markets and higher barriers to entry, and, hence, reduced competition...

The literature on ownership structures made continual use of notions such as cross-holdings and pyramids which are closely related to the vastly increasing network literature. We propose to transfer successfully applied network methods to the corporate control and corporate governance branch as...

The paper briefly sketches alternative models of dealing with principal-agent problems and compares major characteristics of bank-oriented versus marketoriented systems of corporate governance. The ownership structure in Germany is contrasted with evidence for other industrial countries. This...