Swimming Together or Against the Stream? Market Integration of Certified Frozen Salmon Fillets in German Retail Sales

This paper examines price dynamics and market integration among differently certified frozen salmon fillets in the German retail sector. Using scanner data from 2017 to 2020, we estimate pairwise vector error correction models to test for cointegration and the law of one price (LOP) among products certified as Aquaculture Stewardship Council (ASC), Marine Stewardship Council (MSC), and organic, as well as non-certified alternatives. All price series are found to be cointegrated, indicating long-run market integration. The LOP holds between ASC-, MSC-, and non-certified salmon but is rejected for all pairs involving organic products, suggesting that price premiums vary over time. These results point to a distinct market segment for organic salmon, likely shaped by differences in consumer perception, certification familiarity, and retail strategy. The findings contribute to understanding how sustainability labels affect market segmentation and price behavior in the seafood sector.