جغرافیای ناتوانى بازار: اثرات جانبی لبه ـ اثر و مکان و تولید الگوهای کشاورزی ارگانیک

Perceptions of increasing land scarcity and negative impacts of chemical-based agriculture have led to increasing concern regarding the sustainability of food systems. Incompatible production processes among farming systems may lead to spatial conflicts and production losses between neighboring farms, and the magnitude of such losses may depend not only on the scale of each activity, but also on patterns of land use. Such conflicts can be classified as “edge-effect externalities”—spatial externalities whose marginal impacts decrease as distance from the border generating the negative impact increases. This paper tests the hypothesis that edge-effect externalities have influenced the location and production patterns of certified organic farms, using data from California Central Valley certified organic farmers. Using concepts from landscape ecology and spatial statistics, we investigate difference in parcel geometry and surrounding land uses between organic and non-organic parcels. Using a generalized method of moments (GMM) spatially autoregressive econometric model, we demonstrate that both parcel geometry and surrounding land uses influence the probability of a given parcel being certified organic. We conclude with suggestions for policies to encourage development of organic farming regions.