Antiturst enforcement agencies and courts use net effect on price as a touchstone for the legality of mergers. This paper derives a simple, and completely general, condition for implementing that standard when industry equilibrium is static Nash in qualities (Cournot).

This essay is a status report on the development of a new approach to analysis of mergers. This approach replaces market-share- based presemptions with simulations of the effects of mergers within the context of tractable oligopoly models calibrated to the particular characteristics of the...

This paper investigates the properties of four demand systems that have been used to predict the effects of differentiated products mergers: the Almost Ideal demand System (AIDS), logit, linear, and log-linear (constant elasticity).