On the Typical Spectral Shape of an Economic Variable

In a classical article, Granger (1966) argued that the levels of most economic time series have spectra that exhibit a smooth declining shape with considerable power at very low frequencies. He termed it "the typical spectral shape of an economic variable." Granger's assertion has not been examined systematically with international data. We estimate output level spectra for 58 countries, divided into developed, high- income developing, and low-income developing groups. We find the shapes of the estimated spectra to be strikingly similar to Granger's typical shape, particularly for the developed countries.