Why globalization has led to bigger cities

With so much interconnectedness and the ease with which information and goods flow, you would have expected the world today to be more dispersed. Instead, the developing world now has more megacities and greater concentrations of people. Edward Glaeser explains why. Excerpt:

More than 2,500 years ago, the knowledge of the Mediterranean world made its way to Greece through Athens. Twelve hundred years later, Greek and Indian knowledge entered the Islamic world through the Abbasid Caliphate’s House of Wisdom in Baghdad. Eastern wisdom came west again, through Venice and the cities of Spain. The circle continues today, as Western technology makes its way east, again through urban portals like Bangalore. Since there is so much for developing countries to gain economically by integrating with the developed world, the urban gateways to the West attract millions.