A generalized method of impulse identification

Identifying the sources of economic fluctuations has always been an essential part of empirical macroeconomics. This note proposes a method of identification that allows restrictions on impulse responses at arbitrary frequencies. The method includes the popular American Economic Review 79(4), 655¯673, 1989 (AER) procedure as a special case. The implications of the general method is demonstrated via an application to the case of spectral decomposition at the seasonal frequency.