In recent years there has been an emerging debate as to the relative roles of cyclical and structural factors in the performance of the U.S. economy over the last two decades. In structural interpretations, the economy is theorized to have undergone a series of adverse longer-term changes, producing a secular deterioration in industrial performance during the 1970s. Some versions of this thesis call for various forms of industrial or structural adjustment policy to reverse this deterioration. Conversely, in cyclical interpretations, the central role of business cycles implies that the determinants of economic performance have been concerned primarily with macroeconomic policy The implication is that the appropriate policy instruments for bringing the economy back to its long-term growth trajectory are not industrial policies aimed at structural adjustment but traditional stabilization tools.