A laboratory experiment is used to investigate the practical usefulness of two types of models or decision tools employed in social planning. The case is quota setting in a two-species fishery. We find that advice from both a simplistic two-species stochastic optimization model and from two single-species simulation models improve management. The tools are complements rather than substitutes. The optimization model helps subjects to set targets more efficiently, and the simulation model helps subjects to avoid destabilizing overreactions. However, the tools are only approximations, and subjects do not adjust fully for weaknesses of the tools.