Despite the recognition of the eutrophication problem, Baltic-wide environmental targets for nutrient pollution reductions have not been met. Possible factors include inefficiency of environmental policy, and a lack of coordination between environmental policy and policies in other fields like agriculture and energy. The former requires improvements in the design of environmental policy while the latter calls for better coordination of different policies. This chapter reviews studies evaluating nutrient policies in the region, with a focus on economic and cross-disciplinary studies that carry out ex post evaluations of policy instruments. It also investigates optimal monitoring and abatement strategies where both upstream and downstream water quality pose a potential problem, looking at how monitoring and abatement costs, and the regulators’ degree of risk aversion, affect the choice of monitoring strategy.