Cournot competition in a differentiated oligopoly

This paper studies product-quantity equilibria in an oligopoly. Products are interpreted as “qualities” and each firm chooses a quality-quantity pair, simultaneously. It is well known that a pure-strategy equilibrium in product-price pairs does not exist in this model, but a pure-strategy equilibrium in product-quantity pairs exists. Furthermore, in an example widely studied in the literature, the equilibrium has nice asymptotic properties.