Abstract: | Land set aside programs can provide substantial economic benefits in distorted agricultural markets. Their incidence of use is increasing in the US, Canada and particularly in the EC. Voluntary annual programs have a small negative impact on short run food security while more permanent programs have slightly larger effects. The long run impact on food security is determined by whether the program leads to soil conservation or not. Most set aside programs used in Canada, the US and EC have some negative implications for food security. A well designed set aside can enhance long term food security with a limited effect short run food security |