What do we know about urban sustainability? A research synthesis and nonparametric assessment

Urban sustainability has become a burgeoning practical and scholarly enterprise over the last two decades. Yet, there have been few attempts to systematically assess what cumulative knowledge this research is generating. We advance our understanding of urban sustainability by synthesising extant empirical findings to gauge progress made towards developing theoretical insight, and then testing a nonparametric predictive model that helps overcome methodological challenges in this literature. Drawing data from two national surveys of US local governments, we find that although organisational capacity appears to be the most important predictor, the broad range of activities grouped under the banner of urban sustainability' rely on distinct causal mechanisms, and use of composite models and measures of sustainability may hinder theoretical advancement. Implications for future research are discussed.