Is growth possible in all OECD regions? Evidence suggests that it is. Helping underdeveloped regions to catch up with more developed ones will have a positive impact on a country's national growth overall, and such growth helps to build a fairer society, in which no region's citizens are left behind. This publication draws on case studies of 23 regions from ten OECD countries: France (Aquitaine, Midi-Pyrénées, Nord-Pas-de-Calais), Germany (Brandenburg, Sachsen-Anhalt), Hungary (Central Transdanubia - Kösép-Dunántúl), Italy (Marche, Sicilia), Mexico (Chiapas, Durango, Estado de México, Jalisco, San Luis Potosi, Zacatecas), The Netherlands (Zuid-Nederland), Poland (Lubelskie, Podlaskie, Wielkopolskie), Spain (Principado de Asturias), the Slovak Republic (Vychodne Slovensko), and the United Kingdom (North East - Tyne and Wear, North West - Manchester, Yorkshire and Humberside - Leeds).