This CAE working paper introduces some of the subject matter of farmland protection. The author draws upon the discipline of economics for the rationale behind farmland protection policies, to explain conditions surrounding the farmland market and as a basis for identifying successful farmland policies. Farmland protection is centrally concerned with the land market and conditions under which buyers and sellers who both willing and eligible to negotiate will do so. The author reviews the effects of farm income and wealth, the value of farmland as well as the effects of farm policy, tax policies and land use controls on land values. Three prerequisites to success in farmland protection policies are identified. Successful programs must acknowledge that a farm is more than land and focus both on land and the opportunities and incentives that make land a farm. Secondly, they must distribute the cost fairly, or at least in a manner generally acceptable the population. And thirdly, all levels of government must be involved since economic systems are porous, not isolated or self contained. The two farmland protection programs that meet these criteria better than programs in any other states, those in New York and Michigan, are described. The author concludes that economics can help us understand the forces that bring about land use change and the relationships between incentives and action that may sustain a certain land use pattern.