Since the 1960s hydrocarbons like crude oil and natural gas have been the most important energy source to fuel the world economy. Despite high recent growth rates for renewable energies, hydro- carbons are expected to be a dominant source of energy for several decades to come. In the last 20...

This paper considers the question of whether changes in persistence have occurred during the long-run evolution of U.S. prices of the non-renewable energy resources crude oil, natural gas and bituminous coal. Our main contribution is to allow for a structural break when testing for a break in...