Regions are at the forefront of governments’ efforts to boost growth, improve well-being and tackle inequalities, but the economic crisis has increased the gap in GDP per capita between leading and lagging regions in half of the OECD countries. The largest increase in the gap between the best 10% performing regions and the bottom 10% of regions, more than 8 percentage points, occurred in Denmark, Ireland and Slovak Republic. Where regional disparities were reduced, this was due to the decline of the richest regions rather than a catching up of the poorest regions, except for China and India. In three-quarters of the countries studied, the GDP per capita in the best 10% performing regions decreased between 2008 and 2010, with the highest decrease (12%) observed in Canada and Estonia.