To evaluate the effect of climate change on crop productivity, several econometric studies have considered farm responses to climate change as well as the agronomic impact of such change. These models assume profit maximization as a principle of farm behavior. Climate change generally affects not only the average weather condition, but also the variability of weather. Most existing climate models project an increase in the probability of extreme weather such as drought. Hence, if the weather condition during crop season is a risk factor for farmers, climate change may increase the level of risk, and the farmers must respond to it.
By assuming expected utility maximization on the part of farmers, this paper develops a simple reduced-form econometric model which takes into consideration the responses of farmers to the change of weather risk. The model is then applied to wheat production in Adana, which belongs to a semi-arid area of Turkey. The estimated result suggests that the farmers will react to an increase of weather variability by decreasing the expected yield of wheat. Finally, by combining the results of the econometric model with those of the climate model given by other studies, the impact of climate change on the yield is quantified. The results show that, if we take into consideration the weather variability risk factor, climate change will lead to a decrease in the yield of wheat in all regions of the area studied, but, if not, climate change will not have a clear impact on the yield.
抄録全体を表示