Since the Second World War, European nations experienced two distinct periods of economic change. First, there was the long period of high and sustained growth from the late 1940s through to the early 1970s, which narrowed signi cantly the gap between American and west European levels of productivity that had existed at the start of the period. By the late 1960s, rapid growth and structural change seemed to be the natural order of things and the old trade cycle depressions a thing of the past.