Adjustment of small, medium, and large Vermont dairy farms to successively tighter constraints on phosphorus loss was modeled using linear programming. Aggregate response to phosphorus control was estimated for an area from farm marginal costs. Medium and large farms have lower costs than small...

Nutrients from municipal and agricultural sources are probable causes of a zone of hypoxic waters in the Gulf of Mexico. Costs of control between the two sources vary widely. We examine cost saving that could be obtained by allowing point sources to purchase nitrogen loss reductions from...