The compact city in empirical research: A quantitative literature review

The ‘compact city’ is one of the most prominent concepts to have emerged in the global urban policy debate, though it is difficult to ascertain to what extent its theorised positive outcomes can be substantiated by evidence. Our review of the theoretical literature identifies three main compact city characteristics that have effects on 15 categories of outcomes: economic density, morphological density and mixed land use. The scope of our quantitative evidence-review comprises all theoretically relevant combinations of characteristics and outcomes. We review 321 empirical analyses in 189 studies for which we encode the qualitative result along with a range of study characteristics. In line with theoretical expectations, 69% of the included analyses find normatively positive effects associated with compact urban form, although the mean finding is negative for almost half of the combinations of outcomes and characteristics.