Mean reversion versus random walk in oil and natural gas prices

Abstract

The goals of the paper are as follows: (i) review some qualitative properties of oil and gas prices in the last 15 years; (ii) propose some mathematical elements towards a definition of mean reversion that would not be reduced to the form of the drift in a stochastic differential equation; (iii) conduct econometric tests in order to conclude whether mean reversion still exists in the energy commodity price behavior. Regarding the third point, a clear “break” in the properties of oil and natural gas prices and volatility can be exhibited in the period 2000–2001.