The topic of this paper is ozone smog or tropospheric ozone pollution and the assessment of one aspect of this problem: impacts on agricultural crops. However, the techniques and their problems are applicable to a wide range of impacts from materials damages to human health effects. In addition, the methods explained have been applied to agricultural damages related to both acid deposition (see Adams and McCarl, 1985a) and global climate change (Adams et al., 1988). The concentration here is on the estimation of the tangible benefits from policies 10 reduce tropospheric ozone concentrations.