Accounting for Oil Price Variation and Weakening Impact of the Oil Crisis

Recent empirical studies reveal that the oil price-output relationship is weakening in the US. Oil price-output correlation is less negative, and output reduction in response to oil price rise is more moderate after mid 1980s. In contrast to the conventional view that there have been changes in the economic structures that have made output less responsive to oil price shocks, we show that what have changed are the sources of oil price variation. We develop a DSGE model where oil price and US output are endogenously determined by the exogenous movements of US TFP and the oil supply. Having no changes in economic structure, our model yields dynamics of the oil price and output that show a weakening in the oil price-output relationship. There are changes in the way that the exogenous variables evolve. Two changes are important. First, oil supply variation has become moderate in recent years. Second, oil supply shortage is no longer followed by a large decline in TFP. We show that less volatile oil supply variation results in less negative oil price- output correlations, and a smaller TFP decline during oil supply shortfall implies a smaller output decline during oil price increases.