Fish pricing is strange. Calculating the price of a fish filet is wildly different from pricing a steak filet. For cattle and other livestock, prices are based on the cut, not on the size of the steer or hog that produced the meat. Yet for fish, size matters.
Here’s an example: like most commodities, the price of fish classified as fresh Atlantic Superior Salmon shifts with the market. The NASDAQ Salmon Index tracks this price. On the index, salmon prices are broken down into weight classes, like scaly wrestlers: one to two kilograms, two to three kilograms, all the way up to nine kilograms and more. In each of these categories, a kilogram of salmon commands a slightly different price.
This isn’t specific to salmon. Eric Sjöberg, an economist at the University of Utah, says that the pattern holds for a range of fish. In a study, Sjöberg shows how for four fish—haddock, hake, lemon sole, and saithe—size is “a crucial determinant” for price per kilogram. On average, he says, the total value of a catch can rise or fall depending on whether a fisherman pulls in more small fish or more big fish, even if the total mass of fish is the same.
