Aggregating economic knowledge for use at national, regional, sector, and farm level

Abstract

Decisions concerning land use, agricultural production and environmental management are taken at many different levels, ranging from the national to the farm level. For proper decision making, policy makers at each level should dispose of relevant, reliable and consistent information. National or regional policy makers require information on what happends at farm or regional level. Can such information be supplied by aggregating farm level knowledge into sector, regional or national models? The author explores this questions in three steps. First the methodological issues in aggregation of knowledge are discussed. Aggregation problems for individual data, response functions and systems models are described and conditions for correct aggregation are formulated. Spatial and temporal aggregation is discussed and juxtaposed with the exploration and analysis of disaggregated data. Five frequently occuring aggregation biases are discussed. Secondly the use of knowledge by policy makers is treated. Differnt levels of policy making and their specific requirements are distinguished. Problems of integrating farmers and policy makers perspectives are reviewed. Political and agro-ecological boundaries for aggregation purposes are compared and the friction between more detailed model specification and the use perspective is explored. Finally six suggestions for improving the integration of policy making and (dis)aggregated analysis are made: early interactions between policy makers and analysts; more empirical studies on policy making; a shift from theory development to empirical application; the adoption of participatory action research elements in agro-ecological research; a focus on interventions instead of (eco)systems; and the integration of disciplines along the different hierarchical levels.