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| 1 |
ID:
171428
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| Summary/Abstract |
The consumption of fossil fuels has resulted in the increasing environmental pressure and a series of environmental pollution problems. Taking four Chinese cities (Beijing, Tianjin, Shanghai and Chongqing) as examples, the reasons of fog and haze caused by multi-factor coupling were studied in this paper. Firstly, the contribution of four factors (including building completed area, thermal power generation, gross industrial output value and wind speed) to fog and haze in Tianjin was analyzed, and then these four cities were compared to explore the impact of the same factor on fog and haze in different regions. Secondly, the functional relationships between these four factors and air quality index (AQI) were obtained based on statistical data, and a sensitivity analysis was carried out to get the dominant factor of fog and haze in these four cities. Finally, the corresponding policy recommendations were given based on different dominant factors of these four cities.
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| 2 |
ID:
166538
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| Summary/Abstract |
A large number of studies on road construction and rail transit have not taken the improvement effect and the substitution effect into account. Using the quarterly data from 2013 to 2016 of 28 cities with metro opened in China, this research firstly compares the improvement effect of road reconstruction with the substitution effect of rail transit construction on air quality. Empirical results show that urban rail construction exerts a greater marginal impact on improving air quality than urban road reconstruction. Then, we employ operation length of urban rail transit as a long-term proxy variable and the length of rail built in season as a short-term proxy variable of rail transit construction to make a further discussion. In general, rail transit has an air pollution-reducing effect in the long run, while the construction of rail transit has a negative short-term effect on air quality. Based on above findings, governments should take measures to conduct convenient and efficient urban transportation network, and guide the construction of rail transit to multi-level development.
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| 3 |
ID:
169891
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| Summary/Abstract |
To analyze the impact of the increase of public transport on the urban air quality will contribute to the sustainable development of urbanization. But many existing studies have not paid attention to the potential endogeneity of estimation, which comes from the fact that the deterioration of air quality would in turn affect the policies of public transport investment. This paper attempts to control this endogeneity by introducing an instrument variable of the urban built-up area into the empirical models. Using city-level data from China, our study adopts 2SLS method and conducts a series of robustness tests to ensure the estimation results more convincing and robust. The results show that the urban air quality could be improved if the city provides more buses for public transport. Moreover, after controlling the endogeneity, the marginal improving effect of increasing the public transport on urban air quality could be larger from 0.082 to 0.678. This finding indicates that the endogeneity bias is likely to cause the underestimation of the improving effect, and may result in some errors of the policy decisions of urban investment.
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