evaluation of clean air and determining the factors affecting tehran citizens’ willingness to pay

due to urbanization and consequent environmental problems in iran, many people have been interested in improving the weather quality. lack of information about health risks as a result of pollution is a big obstacle which stops policy-making in this regard. the present study examines the type of relationship between low air quality and tehran citizens’ willingness to pay in order to improve weather quality. to achieve the goals two-stage heckman method has been used so as to quantify the tendency to pay in people (wtp) for improving weather quality. a sample including 1010 tehran citizens have been used according to random sampling method and the citizens have been interviewed face to face. the results have revealed that 55.7 percent of respondents are able to pay wtp and monthly average per person has been estimated about 3500 rials. a probit model for relationship between endogenous variables and wtp and a regression equation for getting the average willingness to pay have been used and what has been concluded is that age, income and the number of years spent in education have a significant effect on wtp and the women, and those suffering from respiratory diseases and habitants of polluted areas have more willingness to pay than others. unlike developed countries, most respondents consider the government in charge of weather quality improvement and 44 percent of people were not motivated at all to spend money or make any effort to improve weather quality.