Why do some regions grow faster than others, and in ways that do not always conform to economic theory? This is a central issue in today's economic climate, when policy makers are looking for ways to stimulate new and sustainable growth. OECD work suggests that there is no one-size-fits-all answer to regional growth policy. Rather, regions grow in very varied ways and the simple concentration of resources in a placeis not sufficient for long-term growth. This report draws on OECD analysis of regional data (including where growth happens, country-by-country), policy reviews and case studies. It argues that it is how investments are made, regional assets used and synergies exploited that can make the difference. Public investment should prioritise longer-term impacts on productivity growth and combine measures in an integrated way. This suggests an important role for regional policies in shaping growth and economic recovery policies, but also challenges policy makers to implement policy reforms.