Ben Derudder is Professor of Human Geography at Ghent University. He is also Associate Director of the Globalization and World Cities research group and network (GaWC). His research focuses on the conceptualization and empirical analysis of transnational urban networks, the importance of business travel in the space economy, and the impact of the globalization of transport and production on urban development. Frank Witlox is Professor of Economic Geography at Ghent University. He is also Associate Director of the Globalization and World Cities group and network (GaWC), and a visiting professor at the Institute of Transport and Maritime Management Antwerp (ITMMA). His research focuses on transport economics and geography, city logistics, world cities and globalization, and urban planning.