Book excerpt: Production economics is that branch of microeconomics that examines producer decisions. This book focuses on the empirical estimation of these relationships using primal, dual, and differential specifications. The primal specification models production decisions based on the production function — estimation of the input/output relationship and the derivation of optimization behavior from this technical relationship. The dual approach estimates production decisions using economic information such as input and output prices. The textbook then develops the linkages between these relationships. The differential specification is an alternative approach derived from changes in the first-order conditions from cost minimizing behavior. In each case, the theoretical development is followed by different empirical specifications that can be used to estimate the producer's choice.