ABSTRACT
This chapter identifies and analyzes that economics is distinct from the other social sciences not so much by virtue of the kind of real-world mechanisms with which it deals, but because of the way in which mechanisms. It highlights the role that economists' methodological commitments play in defining what counts as a mechanism in economics. The chapter discusses the alleged connection between mechanism and methodological individualism and the role of mechanisms in causal inference from statistical data and in extrapolation. Economists' commitment to the doctrine of methodological individualism emerges with particular clarity from the belief that macroeconomics should be built on microeconomic foundations. Knowledge of mechanisms has been claimed to play a key role in making causal inferences from statistical data more secure. The problem of extrapolation concerns how to justify transporting causal claims from one context, for example a laboratory experiment or one country, to another, the real world or another country.
