In recent years, our understanding of the nature of energy price shocks and their effects on the economy has evolved dramatically. Only a few years ago, the prevailing view in the literature was that at least the major crude oil prices increases were exogenous with respect to the OECD economies and that these increases were caused by oil supply disruptions triggered by political disturbances in the Middle East. This view has little empirical support. Likewise, the popular notion that OPEC constitutes a cartel that controls the price of oil has not held up to scrutiny. At the same time, there has been increasing recognition of the importance of shifts in the demand for oil. Recent research has provided robust evidence that oil demand shocks played a central role in all major oil price shock episodes since the 1970s.