what is the primary function of global cities?

Urban sprawl, poor public transport infrastructure and a lack of basic services such as energy, water and waste can hinder accessibility and mobility, increase air pollution and exacerbate urban poverty, reducing the economic benefits of urban concentrations and increasing costs. However, poorly managed urban growth is likely to have substantial economic costs. Similarly, well-managed cities in high income countries could continue to concentrate national economic growth, through re-densification and the rollout of innovative infrastructure and technologies. The economic potential is driven by raised productivity resulting from the concentration of people and economic activities in cities that leads to a vibrant market and fertile environment for innovation in ideas, technologies and processes. If managed well, the potential benefits of this urban growth are substantial. India, Nigeria and Indonesia will also experience rapid population growth. By 2030, China’s cities alone will be home to nearly 1 billion people.

Between 20, the urban population is projected to increase by around 2.5 billion people, reaching 66% of the global population. Urbanisation is one of the most important drivers of productivity and growth in the global economy.

What is the primary function of global cities?