Walsh, Patrick Paul; Mariuzzo, Franco; Whelan, Ciara - Department of Economics, Trinity College Dublin - 2005
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 di?erentiated products industries. We...
