Story Name: Air Pollution and Mortality
Story Topics: Environment
Datafile Name: SMSA
Methods: Outlier
, Transformation
, Regression
Abstract: Researchers at General Motors collected data on 60 U.S.
Standard Metropolitan Statistical Areas (SMSA's) in a study of whether air
pollution contributes to mortality. The dependent variable for analysis is age
adjusted mortality (called "Mortality"). The data include variables measuring
demographic characteristics of the cities, variables measuring climate
characteristics, and variables recording the pollution potential of three
different air pollutants.
The pollution variables are highly skewed. A logarithm transformation makes
them much more nearly symmetric. Various multiple regression models may be used
to determine whether air pollution is significantly related to mortality.
Image: A partial regression plot of Education from the regression of
Mortality on Education, pop density, %NonWhite, Rain and Log(NOx).