IN HIS EFFORTS to make his farm pay, the farmer must decide what to produce and how to produce it and what to sell and how to sell it. His success depends on his making the right decisions on these questions. These questions come up nearly every day in the year and decisions must be based on a knowledge of principles and facts and not on some simple rule of thumb. Farm economics deal with the principles one needs to understand and the information one needs to have in order to make correct decisions. Farmers who understand these principles and know how to apply them are the ones who make the most out of farming.