them measure the benefits of policies to tackle pollution and,when compared with costs of implementation,to devise cost-effective air quality management plans. This study also presents the results of 2013 Global Burden of Disease Study(GBD 2013 Col- laborators 2015).The GBD measures illnesses and premature deaths from a multitude of causes and risk factors around the world,including air pollution.It offers the most extensive estimates of exposure and trends in air pollution levels and their associated burden of disease. The GBD effort dates to the early 1990s when the World Bank commissioned the original GBD study for feature in its World Development Report 1993:Investing in Health.Since 2010, the Institute for Health Metrics and Evaluation(IHME)at the University of Washington,Seat- tle,has steered the GBD study,with the latest set of estimates for 2013. Methodology The disease burden attributable to air pollution is estimated by first measuring the severity of air pollution and the extent to which people are exposed to it (Brauer et al.2016; Cohen et al.n.d.).The GBD evaluates exposure to outdoor (ambient)air pollution as well as indoor air pollution in households cooking with solid fuels.The GBD approach to estimating ambient air pollution aims to make the greatest use of information from different sources in the most reasonable way possible,combining data from ground monitoring with satellite observations and chemical transport models.Exposure to household air pollution is estimated from a combination of data on the proportion of households using solid fuels,estimates of indoor pollution concentrations associated with fuel use,and the ratio of personal to area exposure. The GBD then evaluates how personal exposure raises people's relative risk of contracting ill- nesses such as ischemic heart disease,stroke,chronic obstructive pulmonary disease,lung cancer,acute lower respiratory infections,and pneumonia.Elevated risk among the exposed population translates into a higher portion of deaths from these conditions each year,which are attributed to air pollution. Using the GBD estimates of premature mortality attributable to pollution,this study values the economic costs in dollar terms following two different approaches:(1)a welfare-based approach that monetizes the increased fatality risk from air pollution according to individuals' willingness to pay(WTP);and(2)an income-based approach that equates the financial cost of premature mortality with the present value of forgone lifetime earnings.Each of these approaches is given equal weight in this report,although they are tailored to different purposes. The welfare-based approach is intended to measure the economic costs of fatal health risks to the individuals that make up a society.By increasing people's risk of contracting a deadly ill- ness,air pollution represents a threat to the many things they value,including consumption, leisure,good health,and simply being alive.This value is reflected in the WTP,which captures the trade-offs that individuals are willing to make to reduce their chances of dying.The value of statistical life(VSL)represents the sum of many individuals'WTP for marginal changes in The Cost of Air Pollution:Strengthening the Economic Case for Action xiThe Cost of Air Pollution: Strengthening the Economic Case for Action xi them measure the benefits of policies to tackle pollution and, when compared with costs of implementation, to devise cost-effective air quality management plans. This study also presents the results of 2013 Global Burden of Disease Study (GBD 2013 Col￾laborators 2015). The GBD measures illnesses and premature deaths from a multitude of causes and risk factors around the world, including air pollution. It offers the most extensive estimates of exposure and trends in air pollution levels and their associated burden of disease. The GBD effort dates to the early 1990s when the World Bank commissioned the original GBD study for feature in its World Development Report 1993: Investing in Health. Since 2010, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, Seat￾tle, has steered the GBD study, with the latest set of estimates for 2013. Methodology The disease burden attributable to air pollution is estimated by first measuring the severity of air pollution and the extent to which people are exposed to it (Brauer et al. 2016; Cohen et al. n.d.). The GBD evaluates exposure to outdoor (ambient) air pollution as well as indoor air pollution in households cooking with solid fuels. The GBD approach to estimating ambient air pollution aims to make the greatest use of information from different sources in the most reasonable way possible, combining data from ground monitoring with satellite observations and chemical transport models. Exposure to household air pollution is estimated from a combination of data on the proportion of households using solid fuels, estimates of indoor pollution concentrations associated with fuel use, and the ratio of personal to area exposure. The GBD then evaluates how personal exposure raises people’s relative risk of contracting ill￾nesses such as ischemic heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, acute lower respiratory infections, and pneumonia. Elevated risk among the exposed population translates into a higher portion of deaths from these conditions each year, which are attributed to air pollution. Using the GBD estimates of premature mortality attributable to pollution, this study values the economic costs in dollar terms following two different approaches: (1) a welfare-based approach that monetizes the increased fatality risk from air pollution according to individuals’ willingness to pay (WTP); and (2) an income-based approach that equates the financial cost of premature mortality with the present value of forgone lifetime earnings. Each of these approaches is given equal weight in this report, although they are tailored to different purposes. The welfare-based approach is intended to measure the economic costs of fatal health risks to the individuals that make up a society. By increasing people’s risk of contracting a deadly ill￾ness, air pollution represents a threat to the many things they value, including consumption, leisure, good health, and simply being alive. This value is reflected in the WTP, which captures the trade-offs that individuals are willing to make to reduce their chances of dying. The value of statistical life (VSL) represents the sum of many individuals’ WTP for marginal changes in 1700234_Cost of Pollution.indd 11 8/31/16 3:36 PM