Chapter 6 Sectoral economics This chapter discusses a common set of methods that are not currently in wide use in either microeconomics or macroeconomics but constitute a core of the methodology for models in many different sectors of the economy. The chapter also provides an overview of the varieties of sectoral models and discusses the ways in which some of the methods of sectoral economics can be used to great advantage in microeconomics or macroeconomics. It is now possible to estimate entire models and to solve these models using nonlinear programming or stochastic control theory methods. These methods permit the consideration of accurate models and the inclusion in the analysis of the effects of uncertainty. The progress in sectoral modeling is based on the foundation of earlier work in activity analysis linear programming and the solution of models with economies of scale that permits the development and solution of realistic models with many commodities processes productive units plants and markets.