Please find the abstract for next month's SOCAAR seminar attached.  

Uncertainty and Variability in Social Costs for Air Quality

Elisabeth Gilmore
Assistant Professor  
School of Public Policy
University of Maryland, College Park

Choosing between alternative products, processes and policies requires credible 
information on the private costs and the social costs, specifically human health and 
ecosystem effects. To generate a social cost of air quality in $/ton of emission, an 
impact pathway approach, which traces the emissions through to the monetization of the 
associated human health effects, is frequently employed. An important step in this 
process is transforming the emissions to their equivalent ambient concentrations. The 
assumptions in the air quality models, however, are rarely evaluated and may introduce 
unknown error into literature values. 

In this presentation, we evaluate the sources of variability and uncertainty in the social 
cost estimates for air quality with the goal of providing guidance on the selection and 
interpretation of literature values. First, we conduct a critical review of the reduced form 
values in literature. Second, we develop new social cost estimates using the ‘state of 
science’ 3-D chemical transport model, the Particulate Matter Comprehensive Air Quality 
Model with extensions (PMCAMx). Specifically, we translate emissions of elemental 
carbon, nitrogen oxides, sulphur dioxide, and volatile organic compounds in fine 
particulate matter (PM2.5) in different locations and using different model 
parameterizations. We then monetize the PM2.5 using the long-term premature mortality 
concentration response function and the value of a statistical life. We calculate social 
costs that differ from other literature values by a factor of two to more than ten for both 
reactive and non-reactive compounds. This suggests that variability in the modeled 
transport and chemistry can have an important influence on the estimates. Our results 
recommend caution in the use of literature values for the social cost of air quality 
emissions for benefit-cost analysis and externality pricing.

March 6, 2013, 3 - 4 pm
Wallberg Building, 200 College Street, Room 407

This seminar will be recorded and will be available after the talk at the following 
site: 
http://www.socaar.utoronto.ca/collaboration/SOCAAR_Seminar_Series.htm
Recordings of past SOCAAR seminars can also be found here.