ABSTRACT
The chapter analyzes the notions that are central to the ontology of macroeconomic aggregates: reduction, supervenience, and emergence. It investigates the extent to which the leading model used for macroeconomic policy analysis (the canonical dynamic-stochastic general-equilibrium model) can be said to capture the ontology of macroeconomic aggregates. It criticizes Hoover’s claim that macroeconomic aggregates do not fully reduce to the microeconomic quantities, of which they are composed. And it draws conclusions for the type of program of microfoundations that I think macroeconomists should adopt.
