What Are We Learning about the Long-Run?

An attempt is made to link together earlier definitions of the long run found in micro and macro economics with recent developments in econometrics, specifically cointegration. It is suggested that the links are not strong and that most of the previou s work in econometric theory has been unnecessarily overprecise. The possibility of embedding cointegration theory into a very general, nonlinear theory is suggested. An example uses a nonlinear relationship between U.K. short- and long-run interest rates proposed by Frank Paish (1966). Copyright 1993 by Royal Economic Society.