Abstract
The Ricardian approach to estimating climate change impacts is an important technique for incorporating how adaptations modulate the overall effect. Past Ricardian work expresses climate sensitivities in terms of local effects only, ignoring the influence on adaptation of broader-scale social, environmental and economic factors. This paper extends the Ricardian approach to account for influences at multiple spatial scales. Results from multi-level modeling support the hypothesis that a county''s Ricardian climate sensitivity is influenced not only by its climate but also by social factors associated with the climate of the agro-climatic zone in which it is located. The model estimates a non-linear, hill-shaped relationship between July maximum temperatures and agricultural land values, with initial increases beneficial in all counties but more beneficial in districts of high interannual temperature variability. Farmers and institutions in districts of high variability have therefore adapted to be more resilient to variability than farmers in areas of comparatively stable climate. However, the underlying reasons for this lessened vulnerability are unclear and may be associated with unsustainable land-use practices. Future research should investigate the precise form of these local and extra-local adaptations to determine if implementing the adaptations elsewhere would compromise agricultural system sustainability.