The paper aims at assessing the costs and benefits of antitrust enforcement. The analysis starts with an investigation of why competition is typically worth protecting followed by a collection of empirical evidence which shows that competition actually needs protection by antitrust policy in...

Determinants of a firm's export-sales ratio (degree of internationalisation) are frequently discussed in the literature related to individual firms' export activities. Stylised facts show a positive relationship between firm size and firm age on the one hand and the firm's export-sales ratio on...

Within the last three years, Google has acquired YouTube and DoubleClick and has attempted to control part of Yahoo!'s search advertising business. Two of the deals have not raised antitrust concerns by competition authorities. I review these deals with a focus on consumer welfare. Consumers are...

The increased diffusion of computers is one of the fundamental changes at workplaces in recent decades. While the majority of workers now spend a substantial fraction of their working day with a computer, research on the wage effect of computer use effectively came to a halt after DiNardo and...

This paper studies the aggregate substitution and expansion effects triggered by changes in input prices, in a context where firms supply a homogenous commodity and compete in quantities à la Cournot. We derive a sufficient condition for the existence of a Cournot equilibrium and show that this...

Using a large linked employer-employee data set, this paper presents new evidence on the wage premium under collective bargaining contracts in western and eastern Germany. The novel feature of our analysis is that we use a longitudinal data set. In contrast to previous studies, we seek to assess...

Normalising CES production functions in the calibration of basic dynamic models allows to choose technology parameters in an economically plausible way. When variations in the elasticity of substitution are considered, normalisation is necessary in order to exclude arbitrary effects. As an...

This paper compares trends in wage inequality in the U.S. and Germany using an approach developed by MaCurdy and Mroz (1995) to separate age, time, and cohort effects. Between 1979 and 2004, wage inequality increased strongly in both the U.S. and Germany but there were various country specific...

This paper empirically estimates the effects of a new thin-capitalization rule on the financing behavior of German corporations employing a fixed effects difference-in-difference approach. We compare treatment and control groups separated by a hypothetical application of the new rule in three...

Contractual and regulatory provisions for access affect incentives to invest in an upgraded network and, in particular, a next-generation access network. Investment decisions are made under uncertainty and have to be made over time. This papers provides a framework for taking uncertainty, risk...