%0 Journal Article %T XXQ FACTORS FOR SUSTAINABLE URBAN DEVELOPMENT: A SYSTEMS ECONOMICS VIEW %A Peter Nijkamp %J Romanian Journal of Regional Science %D 2008 %I Romanian Regional Science Association %X Modern cities turn increasingly into functional areas seeking for a balance between agglomeration forces and urban quality of life. This paper will address the issue of sustainable urban development from a quality (performance) perspective. It aims to identify the critical access factors for the highest possible quality (XXQ) of the urban economy. A plea is made for a coherent methodological approach based on a systems economic view. In addition to a sketch of recent dynamic trends in urban systems in OECD countries, it pays attention to theories on urban growth and performance. Next, five critical success conditions for a high performance of cities will be presented in a coherent urban systems economics framework. The policy lessons of the analysis will form the last part of the paper. %K urban development %K sustainability %K critical access factors %K systems economics %U http://www.rrsa.ro/rjrs/N2-NIJKAMP.PDF