OxTalks will soon move to the new Halo platform and will become 'Oxford Events.' There will be a need for an OxTalks freeze. This was previously planned for Friday 14th November – a new date will be shared as soon as it is available (full details will be available on the Staff Gateway).
In the meantime, the OxTalks site will remain active and events will continue to be published.
If staff have any questions about the Oxford Events launch, please contact halo@digital.ox.ac.uk
Using an aggregative games approach, we analyze horizontal mergers in a model of multiproduct-firm price competition with a demand system that satisfies the Independence of Irrelevant Alternatives (IIA) property. We show that the Herfindahl index provides an adequate measure of the oligopoly distortions to consumer surplus and aggregate surplus, and that the induced change in the naively computed Herfindahl index is a good approximation for the market power effect of a merger. We also provide conditions under which a merger raises consumer surplus, and conditions under which a myopic, consumer-surplus-based merger approval policy is dynamically optimal. Finally, we study the aggregate surplus and external effects of a merger.
