Additionally, we analyse the current relationship between pollution emissions and car characteristics in order to orient policy formulation. We find a positive relationship between emissions rates and horse power, concluding that although the current value-added sale car tax is not environmental harmful, a tax differentiating clean from dirty models, within each tax bracket, could create substantial incentives for emission control in the future.
Urban air pollution is a serious environmental problem in developed as well as in most developing countries. In the case of Brazil, air pollution concentrations have been rapidly increasing in the major urban areas over the last decades. As elsewhere, this expansion has been caused mainly by the increasing use of vehicles. Today, emissions from vehicles are the major source of air pollution in Brazil's largest cities. In 1997 in São Paulo, for example, private cars were responsible for approximately 75% of carbon monoxide (CO), 73% of hydrocarbons (HC), 23% of nitrogen oxides (NOx) and 10% particulate matter (PM)
Costs associated with high air pollution concentrations in large cities are known to be important. Human health costs predominate,