Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This study utilizes a frequency domain approach to decompose the prices of 21 primary commodities into transitory, supercycle, and permanent components from 1900 to 2022. The results reveal the presence of four heterogenous supercycles, with an average duration of 24 years. These cycles, however, contribute only modestly to price variability while the permanent component contributes the most. The paper also shows that different commodities are consistent with various theories of price movements, including Engel's law, Hotelling's rule, and Schumpeter's cyclicality (or Kondratieff's waves).