Product Quality, Cost Asymmetry and the Welfare Loss of Oligopoly

When competition is tough, firms which do not implement the least expensive technology are forced to exit, or the low cost firms are able to increase their market share. Persistent cost or profit differences require some form of restricted entry, specific intangible assets or oligopolistic co-ordination. If technology or skills is easy to transfer but it is not transferred because of collusion, we have to add a cost side effect ('the staircase')stemming from the non-proliferation of the best technology- to the well-known demand side loss ('the triangle'). This paper presents a model with vertical product differentiation and develops a method which disentangles cost differences coming from vertical product differences and those coming from other sources. Data for the paper industry in the EU, in the US and in Japan indicate that cost differences are large. If at least some part of them comes from oligopolistic co-ordination, then the welfare loss of oligopoly is much larger than the usually measured demand side welfare loss.