This book presents a perspective on the role of modeling that has relevance to both practice and theory. The authors provide an empirical assessment of the role of computer models in urban policy decisions, presenting a survey and four detailed case studies focusing on the use of a specific class of computer-based fiscal impact models in American logical governments. The findings are interpreted in light of this perspeectiv on the social and political dynamics of models in the policy process. From this perspective, called consensus modeling, a model is viewed as a tool for facilitating negotiation, and, thereby, consensus in the policymaking process.