A Perspective on the Current State of Macroeconomic Theory

Historically, microeconomics was the domain of scientific methodology in economics, while macroeconomics attracted less mathematically oriented economists. In recent years, the level of sophistication of macroeconomics has grown dramatically, and that field now attracts many of the most mathematically oriented economists. Nevertheless, the field's set of shared views (i.e., maintained hypothesis) has not grown. The purpose of the scientific method is to permit the maintained hypothesis within a field to grow by establishing a rigorous methodology for deductively deriving and empirically testing hypotheses. The field of macroeconomics has failed that test of scientific success during precisely the decades of most rapid growth in the use of scientific methodology. It is argued that the source of the paradox lies in the fact that the inroads of science in macroeconomics have been asymmetric. Central to the definition and objectives of macroeconomics is dimension reduction and dynamics. Rigorous dimension reduction is impossible without formal aggregation, and complex dynamics is impossible without nonlinearity. Yet applications of formal aggregation theory and nonlinear dynamics to macroeconomics have progressed very slowly, at the time that scientific methodology in other areas of macroeconomics have advanced rapidly. This asymmetry explains the paradox.