For most cities, the possibility of transforming unused property into community and city assets is as yet hypothetical. Fiscal constraints limit the amount of land acquisition, relocation, and demolition that cities can undertake. Private investors, unsure of which neighborhoods have a chance of becoming self-sustaining, are reluctant to take risks in untested markets. Cities need to create citywide planning strategies for land aggregation and neighborhood stabilization and to develop analyses of the risks and opportunities associated with redevelopment opportunities in specific markets. Research seems sorely needed. Although the policy world cannot and will not stand still waiting for academics to design the perfect study or to collect all the data to model the potential effects of various policy options and investments, analysis that can play a more immediately supportive role can and should be done now. (abstract from http://repository.upenn.edu)