Structure and Structural Change in Macroeconomic Theory
Macroeconomic models are built on causal structures that reflect choices made with respect to the variables that are solved from the model and those assumed exogenous. These choices are the ‘closures’ of the model. Differences in closures can lead to stark qualitative differences in the model’s solutions of macroeconomic equilibrium, and should therefore reflect the basic structure of the economy. In order to highlight these differences, closures are discussed first in the context of one-sector models. Closing mechanisms become even more consequential for models that formalize economies with multiple sectors. The second part of the chapter thus extends the discussion to multi-sector models and, particularly, to dual economy models. These models are especially relevant for understanding the process of structural change in developing countries and its implications for growth and development.