Since the 1980s, the workforce in New York, London and Tokyo has been professionalizing with an increasing share of high income earners. While measures of segregation have stabilized, spatial inequality has increased due to gentrification of inner-city neighborhoods and suburbanization of poverty.

Human mobility contributes to economic development but also acts as a major vector for disease importation. By Moritz U.G. Kraemer and Nahema A. Marchal