Uncertainty as a barrier to adoption of mitigation practices in agriculture.

Summary Hidden costs limit the reduction of GHG emissions from agricultural production. Uncertainty is inherent to farmers' production decisions, and impacts them through various channels: beliefs, risk, information, ambiguity, are all barriers that can limit the diffusion of mitigation practices in the agricultural sector. In this thesis we first present a comprehensive literature review on agri-environmental measures and on the different useful approaches to uncertainty in microeconomics and agricultural economics. We then develop an adoption decision model showing that 3 hidden costs related to uncertainty can limit the adoption of new practices in a non-additive way and coexist (option value, risk premium, informational externalities), so that the regulator has to socialize them in a GHG emission reduction objective. Then, we adopt a land conversion model and derive an empirical strategy to estimate the impact of the volatility of grassland yields on the implied values of grasslands in the French forage mix. The multinomial logistic model is estimated by an instrumental approach using meteorological data. Finally, we conduct a survey on a sample of farmers in order to measure their attitudes towards risk and ambiguity (Multiple price list) and to estimate their impact on nitrogen fertilization decisions, in terms of total application and splitting.