Is size-dependent pricing prevalent in fisheries? The case of Norwegian demersal and pelagic fisheries

It is commonly acknowledged that body weight of fish is a key factor in determining market value of landed catch, thus influencing optimal harvest strategies. However, in management strategy evaluations and bioeconomic modelling body size is often an overlooked economic parameter, and there are no systematic studies on prevalence of sizedependent pricing. Here we assess the presence and magnitude of size-dependent pricing in ex-vessel prices of fish in Norwegian fisheries. The data encompass landings of four pelagic and four demersal stocks in Norway in 2000–2010. Linear mixed models and generalized additive models were used to determine the dependence of unit price on weight class as well as on total yield and time (year). The results show a significant positive relationship between weight class and price for seven out of the eight examined fish stocks. The relative effect of body weight on price was the strongest for cod, Greenland halibut, Norwegian springspawning herring and mackerel, lesser for North Sea herring and saithe, and negligible for horse mackerel. These findings demonstrate that size-dependent pricing is common in Norwegian fisheries, and is therefore of high relevance for resource economics and fisheries management.