Estimation of citizens' willingness to pay District 5 of Tehran to improve air quality using a conditional valuation method

Policymakers consider environmental quality, economic growth, and health as important factors in sustainable development. Air pollution is one of the major issues in environmental quality. Failure to pay attention to air pollution leads to increased health costs, increased mortality of children and the elderly, decreased public welfare, increased crime and violence, pollution of ecosystems, etc. Therefore, policymakers and economists consider air pollution as one of the main obstacles to the economic development of countries. In modern urban management, the presence and cooperation of the people are considered as a key component in sustainable urban management. Therefore, examining the preferences of people in dealing with air environmental goods, awareness of the level of economic participation, and willingness to pay can be an effective step to reduce air pollution. In this regard, the Willingness to Pay (WTP) by the residents of District 5 in Tehran to improve air quality has been evaluated. For this purpose, the contingent valuation method was used to obtain the estimates of Willingness to Pay. Then, the feasibility of purchasing electric buses using the public participation in one year and the benefits related to this issue in terms of reducing air pollution costs, noise pollution, fuel consumption, and costs of maintaining diesel buses were investigated in this study.

In this study, the data needed to estimate the WTP to improve air quality were obtained by completing a double-bounded dichotomous choice (DDC) questionnaire. The questionnaires were randomly distributed among the citizens in District 5 of Tehran. The questionnaire consisted of three parts including demographic information, perspectives, and willingness to pay questions. Open-ended approaches were used to determine the willingness to pay in the sample. The SPSS, Shazam, and Wolfram Alpha software packages were used for different estimates and statistical operations. It is to be noted that 557 out of 827 intercity buses in District 5 of Tehran are diesel buses such as Benz O-457, Shahab, Scania, etc. The possibility of replacing worn-out diesel buses with electric buses equipped with night charging was investigated. Then, the necessary data for analyzing the cost, environmental and economic benefits of this project were obtained from Tehran Municipality Bus Organization, a review of the Internal and external sources, and statistics related to the level of public participation.

According to the results, 85.9% of the statistical sample was willing to pay at least between 30,000 to 70,000 Rials per month to improve air quality, and 37.5% of them stated that their maximum WTP was more than 70,000 Rials. Also, 36.7% of those who were not willing to pay or were willing to pay less believed that improving air quality is one of the responsibilities of the Environment Organization and the municipality. This can be interpreted that, although the government and the responsible institutions have a responsibility to improve air quality and promote public health conceding that there is a common language between citizens and institutions related to environmental pollution control, one cannot expect much success in preventing and solving air pollution problems in metropolitan areas. The results revealed that 85.9% of the respondents were positively willing to pay while the average predicted willingness to pay by each person was 61450 Rials per month. The results also showed that the suggested monetary charge, income, and awareness factors affect the willingness to pay. Income and awareness factors had a positive effect, and only the suggested monetary charge factor had a negative effect. For the negative factor of the bid amount, it is emphasized that the probability of saying yes to WTP decreases by an increase in the bid amount. As it was found, the municipality could replace 18 diesel buses with electric buses in District 5 of Tehran using public participation. This plan has a profit of about 26.696 billion Rials to reduce air pollution, noise pollution, fuel consumption, and the maintenance costs of diesel buses.

The results of the study provide insight for the municipality about the amount of income from environmental charges on air pollution that local citizens are willing to pay to improve air quality. Awareness of this amount can be an effective step to plan financing projects to reduce air pollution in the region, such as using the facilities of E-city, giving special scores to private companies to make the E-shopping system competitive to reduce travel demand and pollution during peak hours, optimizing the public transportation system in District 5, investing in air pollution reduction plans and helping public organizations to promote public culture to improve air quality. Since environmental funds are one of the sources of financing public services in the municipality, it is recommended that city managers use public partnership to improve air quality and offset costs.