Cycles à moyen terme des prix mondiaux des matières premières agricoles

Agricultural commody prices have long been recognized as displaying cyclical behavior. The purpose of this study is to provide a new analysis of the medium term cyclical behavior of different agricultural commodity prices through the use of recently developed business cycle methodologies. We identify the cycles, which needs to detrend the series before applying a method closed but not identical to the NBER procedure to determine the timing, frequency and amplitude of price cycles. Then we perform tests of cyclical duration in order to compare the regularity of fluctuations in the cycles against the alternative of random walk behavior. The results provide confirmation of cyclicality for a number of agricultural price series.