Power-law periodicity in the 2003-2004 crude oil price dynamics

In recent months, the crude oil market has shown an abnormal behavior as compared with the previous 20 years. The most relevant feature of it being the high-level prices, well beyond the most pessimistic forecasting of a couple of years ago. The aim of this paper is to show that the crude oil price dynamics in the period from mid-2003 to late-2004 can be described by a piecewise linear increasing trend plus an oscillatory behavior with power-law periodicity. In about mid-December 2003, a transition in the period of the price oscillations was detected. Before and after such a date, the oscillation period decreased and increased with time, respectively. Additionally, after July, 2004, the slope of the trend has suffered a 200% increment, which may indicate that the market instability is becoming stronger.