Evaluating the outcomes of plans: theory, practice, and methodology

Despite calls for performance-oriented and evidence-based planning, the outcomes of land use and environmental plans are rarely monitored or assessed ex post facto (that is, post implementation). As a result, planners cannot know whether or why plans achieve their goals, or learn from the results of past interventions to improve planning practice. This evaluation gap is caused by a lack of methodology to evaluate the outcomes of plans and the difficulty of attributing changes to planning activities. We address this gap by proposing and testing a plan-outcome evaluation (POE) methodology. We demonstrate its broad applicability and usefulness in the context of local plans in New Zealand. The POE methodology will be useful to practitioners and academics seeking to assess the outcomes of plans in countries with western planning traditions.