Measuring the effectiveness of voluntary emission reduction programmes

This paper examines the evaluation of state environmental policies aimed at reducing ground level ozone in order to meet air quality standards set by the US Environmental Protection Agency. Several states with metropolitan areas that violate federal air quality regulations have adopted voluntary emission reduction programmes. These programmes focus on emissions from mobile sources, with the chief source being the automobile. States are allowed to claim credit towards bringing their metro areas closer to compliance with regulations only if they can provide credible evidence that these voluntary programmes are successful in reducing emissions. A model is developed to forecast aggregate traffic volumes so that one can assess the impact of the programme in reducing traffic flows during 'Ozone Action Days'. Background information on the difficulties of measuring the ozone problem and on the recent policies adopted by the US EPA is provided. Using data from the Atlanta, Georgia metropolitan area, the accuracy of the model is demonstrated and preliminary analysis of whether the programmes which began in the summer of 1998 has had the desired impact is provided.