The lack of scientific evidence in urban and regional policymaking is problematic: in order for policy to be credible it must be guided by evidence, not ideology. Benefit–cost analysis has long been the workhorse of policy analysis, but other methods are needed too. This chapter advances one method – the regional adjustment model – and explains how it has been applied within and among regions. Along the way, it delivers an empirical example, by applying the framework to growth and development within the American constellation of metropolitan areas. The chapter concludes that regional adjustment models ought to be used as an instrument of evidence-based policy to address questions related to anthropogenic climate change.