Understanding market demand for common pool resources, such as fish, is important for predicting consequences of sustainable resource management. This article studies how demand functions can be traced out using appropriate supply shifters. We show that wind speed on a fishing trip is strongly correlated with the quantities of Norwegian lobster (Nephrops) available on the Swedish market.

Using wind variables as instrumental variables and data on daily average prices and quantities over a 20 year period we estimate the daily aggregate demand for two types of Nephrops. We find that the demand for both types of Nephrops is highly responsive to price changes and that own-price elasticities are two to three times higher than OLS- estimates suggest. In addition, cross-price elasticities show, in contrast to OLS results, that the two types of Nephrops are close substitutes.