By serving as a key revenue source for online content providers, online advertising has been instrumental in the development of innovative websites. Continued innovation among content providers, however, depends critically on the competitive provision of online advertising. Suppliers of online...

Many experts speculate that U.S. antitrust policy towards horizontal mergers has been too lenient. We estimate the price effects of Whirlpool's acquisition of Maytag to provide new evidence on this debate. We compare price changes in appliance markets most affected by the merger to markets where...

We study competition in the German interurban bus industry two years after its liberalization in January 2013. In addition to a brief characterization of the liberalization process and several general market developments, we provide a detailed analysis of selected market characteristics such as...

We provide an empirical assessment of the German interurban bus industry two years after its deregulation in January 2013. In addition to a general description of key developments of the industry, we use a unique route-level price data set to study both competitive interaction in general and the...

A common approach to merger simulations used in antitrust cases is to calibrate demand from market shares and a few additional parameters. When the products involved in the merger case are differentiated along several dimensions, the resulting diversion ratios may be very different from those...

A raft of articles offered contrasting views on analytic tools for assessing unilateral effects from differentiated products mergers. We revisit this debate to clarify the issues and place them in context. We consider the choice among analytic tools at three stages of a merger assessment -...

Divestitures have received little attention in ex-post evaluations of mergers. In partial remedy we simulate the effects of the Carlsberg-Pripps merger in the Swedish beer market and compare the predicted outcomes with those observed ex-post. There are no important price increases following the...

We investigate the accuracy of UPP as a tool in antitrust analysis when there are cost efficiencies from a horizontal merger. We include model-based, merger-specific cost efficiencies in a tractable manner and extend the standard UPP formulation to account for these efficiencies. The efficacy of...

We study effects on prices and quantities of a takeover in the rather concentrated German interurban bus industry. We empirically asses the effect of the takeover of Postbus by Flixbus on industry key features, using a route-level price data set containing prices for more than 6,000 routes in...

The influence of firms' ability to employ individualized pricing on the welfare consequences of horizontal mergers is examined in location models. In a two-to-one merger, the merger reduces consumer surplus more when firms can price discriminate based on individual preferences compared to when...