Samenvatting

Over the last couple of decades, metropolitan areas around the world have been engaged in a multitude of initiatives aimed at upgrading urban infrastructure and services, in an effort to create better environmental, social and economic conditions and to enhance cities’ attractiveness and competitiveness. Reflecting these developments, many new categories of ‘cities’ have entered the policy discourse: ‘sustainable cities’; ‘green cities’; ‘digital cities’; ‘intelligent cities’; ‘smart cities’; ‘information cities’; ‘knowledge cities’; ‘resilient cities’; ‘eco-cities’; ‘low carbon cities’; ‘liveable cities’; and even combinations, such as ‘low carbon eco-cities’ and ‘ubiquitous eco-cities’. Each of these terms apparently seeks to capture and conceptualize key aspects of ongoing urban sustainability efforts. Closer examination, however, reveals that the terms are often used interchangeably by policy makers, planners and developers alike. In this article we examine the reflection of the wider policy debate in academic discourse. By subjecting the twelve most frequently encountered categories mentioned above to bibliometric analysis, we aim to identify the distinct conceptual perspectives harbored by each of them.