Economics is a diverse undertaking consisting of different branches and schools. Within what one might call “mainstream economics” – which is increasingly dominant – one finds many different activities, each with its own methodological peculiarities and problems. Discussions of many intriguing branches of mainstream economics could have been included in Part IV. Inquiries such as behavioral economics, industrial management, the economics of information, labor economics, game theory, and so forth all raise distinctive and important methodological questions.

Because of space constraints, Part IV contains methodological discussions of only four branches of mainstream economics. In Chapter 16, Kevin D. Hoover examines some of the philosophical issues concerning contemporary econometrics, including some of the problems involved in making causal inferences. In Chapter 17, Hoover addresses the question of how closely linked macroeconomics should be to microeconomics, which has long been one of the central methodological questions concerning macroeconomics. In Chapter 18, Vernon Smith, who won a Nobel Prize mainly for his work in experimental economics probes some of the central methodological questions raised by this relatively new and exciting field, whereas in Chapter 19, Colin F. Camerer explores the possibility that inquiries into neurology might guide economic theorizing.

The remaining two chapters in Part IV discuss two of the most important approaches to economics that compete with mainstream economics. In Chapter 20, James M. Buchanan and Viktor J. Vanberg provide an introduction to the distinctive subjective methodology of Austrian economics and, in Chapter 21, Geoffrey M. Hodgson provides an overview of the way in which institutionalist or so-called evolutionary economists approach the subject.