Over the next fifty years, most new wealth will be accumulated in cities; this includes physical infrastructure (road, rail, electricity, telecommunications and sanitation), productive capital (houses, offices and factories) and knowledge capital (skills, knowhow and ideas). The development of cities will also determine humanity’s ability to preserve natural capital. Consequently, urbanization deserves urgent attention from policymakers, academics and businesses worldwide. The current global urbanization project is peaking and within a century it will be all but over. The richest and fastest growing cities are those which increasingly specialize in knowledge-based sectors, facilitating the flow of knowledge across people, institutions and enterprises. Well-governed, connected, clean and uncongested cities are likely to attract productive capital, talent and creativity. But the consequences of bad governance and inaction over planning can stymie performance and erode human welfare for decades or centuries.