Thresholds defined on the level and change in the HHI (Herfindahl-Hirschmann Index) applied to market shares seem to be the main instrument to select notified mergers for investigation in both the EU and US. We question the use of such a selection rule in differentiated products industries. We...

We develop a theoretical model to study the effects of an ad valorem taxation regime differentiated according to product characteristics (quality) within an imperfectly competitive market. Then to test our theoretical prediction we use yearly data from the Irish automobile market during the...

Consumers' choice set of products within stores can be limited. Ackerberg and Rysman (2005) address this problem by modeling unobserved consumer preferences over products and retail stores, leading to augmented demand specifications. Having Carbonated Soft Drink product level data, where we...

EU Merger Control Regulation No 4064/89 tended to rely on a dominance test, based on the market share of undertakings, to indicate the level and potential changes in market power. The use of such in differentiated product industries is questionable. New EC Merger Regulation No 139/2004...