the Ricardian model pioneered by Mendelsohn et al. (1994) measures directly the impacts of climatic change on land value. Critics of this widely used method, Deschenes and Greenstone (2007), argue that omitted variables (e.g. the possibility to convert a land to a non-agricultural use) resulting from unobserved characteristics of land are key determinants of output and land value. Thus, the Ricardian model may produce some biased estimates. (Note 4) Change in land values may not accurately reflect change in climate conditions. Also, any aspects of future climates that differ from the present conditions will not be accounted for in the Ricardian model.