Cities are home to more than half the people living in OECD countries and almost 50 percent of the output and jobs of many nations is found in their largest city. Though most cities have higher economic growth, foreign investment and labour productivity than the rest of the country, they are also more polluted, crime-ridden and socially disparate. A new OECD report, Competitive Cities in the Global Economy gives case studies and policy recommendations to help cities, often the drivers of national economies, continue to thrive.