Abstract Da Rocha, J-M., and Gutiérrez, M-J. 2011. Lessons from the long-term management plan for northern hake: could the economic assessment have accepted it? – ICES Journal of Marine Science, 68: 1937–1941. An economic working group was convened by the EU's Scientific, Technical and Economic Committee for Fisheries (STECF) in 2007 to evaluate the potential economic consequences of the long-term management plan for the northern hake (Merluccius merluccius) stock. An analysis of all the scenarios proposed by the biological assessment using the Economic Interpretation of ACFM Advice (EIAA) model showed that F at the status quo level was the best policy for both yield and profits, in terms of net present values. This result is counter-intuitive because it seems to suggest that effort costs do not influence economic indicators, whereas it is widely accepted that including costs negatively affects economic indicators. A dynamic age-structured model is applied to northern hake and shows that the optimal fishing mortality that maximizes the net present value of profits is <Fmax. The reason why the EIAA analysis was biased towards scenarios with F > Fmax is also shown.