For some time, many experts have been saying that high-density cities are no longer essential for business success. The internet has made it unnecessary for workers and companies to always be in close proximity. But “creative activities — whether economic, cultural or political — thrive on density. In a global economy, with uncertain markets and changing conditions, the most advanced and speculative sectors need concentrations of resources — talent, management, technological infrastructure and buildings. They need dense environments where information does not simply circulate but gets produced. The geography of the global economy consists of both world-spanning networks and these concentrations of resources, as provided by about 40 global cities.”