Alexander C. Diener is Professor of Geography at the University of Kansas, Lawrence, USA. He works at the nexus of political, social, economic, and cultural geography, engaging topics such as geopolitics and borders, identity and migration, citizenship, development and mobility, and urban landscape change. Joshua Hagen is Dean of the College of Letters and Science at the University of Wisconsin-Stevens Point, USA. His areas of research include borders and border theory; cultural politics of place names; demography, economics, and sustainability; and geographies of the pre-modern world.