We present a general Cournot model in which each ¯rm may sell multiplequality-di®erentiated products. We use an upgrades approach, working not with theactual products, but instead with upgrades from one quality to the next. The prop-erties of single-product Cournot models carry over to the...

We study a Cournot industry in which each firm sells multiple quality-differentiated products. We use an upgrades approach, working not with the actual products but instead with upgrades from one quality to the next. The properties of single-product models carry over to the supply of upgrades,...