Urban public transport and air quality: Empirical study of China cities

Abstract(#br)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

Costs, Impacts, and Benefits of CO2 Mitigation

This volume presents the proceedings of the first international workshop on "Costs, Impacts, and Possible Benefits of CO2 Mitigation" held at IIASA in October 1992. The workshop was co-organized by the Japanese Central Research Institute of the Electric Power Industry (CRIEPI), IIASA, the National Science Foundation (NSF), Yale University, and the Intergovernmental Panel on Climate Change (IPCC). The workshop was held to review current research and analysis of economic costs and possible benefits of measures for responding to global climate change, and to critically evaluate knowledge gaps and future research activities. Technological and economic measures for achieving environmentally compatible development have been and continue to be studied. There are a few studies on the comparative assessment of mitigation and adaptation costs, and the potential benefits of these measures. Since these are long-term issues ranging into the next century, their assessment also requires a degree of understanding of possible development paths the world may take in the absence of global warming. The workshop covered the economics of climate change, its impacts, mitigation costs, policy instruments, and modeling issues. This volume summarizes these proceedings and presents the papers from the workshop

Capturing climate's effect on pollution abatement with an improved solution to the omitted variables problem

Climate greatly affects the SO2 concentration abatement efforts of Mae Moh power plant which burns high sulfur content lignite in Northern Thailand. In summer months, hot air rising draws Mae Moh's SO2 emissions out of the Mae Moh valley. In contrast, temperature inversions in winter months prevent hot air in the valley from rising, resulting in the trapping and concentrating of SO2 emissions in the valley. The climatic conditions that affect Mae Moh's abatement efforts are so complex that adequately modeling them has been elusive. In this paper we use a new analytical technique, BD-RTPLS, which produces reduce form estimates while minimizing the influence of omitted variables, like climate. Using BD-RTPLS and monthly data, we tell Mae Moh how much electricity needs to be sacrificed from which generating units to most efficiently reduce SO2 concentrations in any given month.

Holding Back the Waters: Land Development and the Origins of Levees on the Mississippi, 1720-1845.

Man\u27s efforts to control flooding on the Mississippi began about 280 years ago, but the first 130 years has been neglected in scholarly literature. In spite of abundant primary sources, most histories of flood control on the Mississippi revolve around hydraulic engineering and the contributions of state and federal levee bureaucracies---factors which had almost no impact on the creation of the levee system. Engineers did install the first levee at New Orleans and levees on their own plantations in the 1720s, but the extension of the levee line thereafter was almost entirely the work of private land developers supervised at the local level, first by commandants, then by parish and county governments. The soil of the floodplain accumulated over centuries as sediment deposited by overflows. Its fertility laid the basis for plantation agriculture, with the Mississippi as a means of transport, but overflows destroyed farmers\u27 improvements. Native American hunting farmers who moved in concert with overflows were able to coexist with flooding, but did not conceive of land as property. When European kings began to convert swampland into property by means of grants, the prevention of flooding through levees was made a condition of title. Persons who wanted swampland as property built levees to acquire it. People who did not value land, or lacked the means to levee it, moved on and did not become part of the levee-building community. Since levees must be continuous to be effective, developers of the riverside had to submit to regimentation, coercion, and continuous oversight. Liberty was tempered by the demands of the environment. The records of the era 1720 to 1845 tell a story of levee history quite different from that of the engineers\u27 and post-bellum levee bureaucracies. Sources which reveal the levees\u27 origins are various: letters of commandants, parish police jury and county board of police minutes, state levee laws for local bodies, newspaper accounts of floods, travel journals, tax and census records, and private papers. They tell of a vibrant community of land developers who domesticated the swamps with levees in the interest of survival and prosperity