Farmed salmon represents 20% of the total volume of the world's salmon supply. Norwegian salmon farmers produce more than 50% of the world's farmed salmon. Rapid expansion of this industry raises important issues about market model specification. We specify and test models with varying degrees of market power, including third-degree price discrimination, using Norwegian export data from 1983 to 1988. Results indicate that Norwegian exporters have limited ability to engage in regional price discrimination, although they may have discriminated after the third quarter of 1987. Seasonal price discrimination, however, may have taken place because demand is more inelastic in periods when fresh wild-caught salmon are unavailable.