Differences in the growth performances of OECD countries during the 1990s revived the debate over the underlying causes of economic growth. This debate prompted the OECD to undertake a number of in depth studies into this issue. The main theme can be expressed in a simple question: what has driven economic growth in OECD countries in recent decades? Following on from this, what effects, if any, have other developments not least the spread of information technology (IT) had on the determinants of overall economic growth? How, and how much, do government policies and other aspects of the business environment contribute to long term growth, and what policies should therefore be advocated? And, finally, what impact has restructuring within and between industries had on overall growth performances?