Sea turtle bycatch by commercial shrimp trawlers has been a primary threat to the U.S. marine turtle population for decades. In 1987 the U.S. government passed a federal bycatch regulation that requires all shrimpers to use ‘turtle excluder devices’ (TEDs) while fishing in U.S. waters. This article develops a theoretical model that serves to distinctly identify three ways in which the regulation affects domestic supply: i) directly through escapement when TEDs are used, ii) indirectly by affecting the fishers' choice of avoidance activities, and iii) through an effect on the equilibrium market price. We then empirically estimate the model. The results indicate that, over the 1989–2003 period, the total estimated harvest loss for the industry from TEDs was approximately equal to 2.04%, which is considerably lower than industry claims.

JEL Classification Code: Q21, Q22, Q28, C3