Improving economic performance in U.K. regions outside of London, such as Manchester, faces multiple hurdles to ensure lasting and broad-based growth, Alexander Harvey at Oxford Economics says in a note. Many urban cores remain too weak and too poorly connected to spread growth across entire regions, Harvey says. While Manchester has achieved exceptional economic growth in recent years, this hasn't translated to higher incomes and economic activity in the region's outer boroughs, he notes. "Policymakers must continue to develop critical mass in the center of cities like Manchester and invest in transport connectivity in the outer regions to deepen labor markets, unlock stronger output growth, and enable benefits to meaningfully spread across the entire city-region," Harvey says. (don.forbes@wsj.com)