POPULATION-GROWTH AND AIR-QUALITY IN CALIFORNIA

Demographers are often interested in the environmental impacts of popu lation growth. I examine the impact of growth specifically on air qual ity in California. In recent decades, California has suffered from not oriously polluted air and has experienced rapid population growth. Des pite the population growth, air quality actually has improved since th e early 1980s due to aggressive regulatory efforts. Using data for 56 counties, I analyze the contribution of population growth to trends in atmospheric emissions of five regulated pollutants from 1980 to 1990, controlling for trends in per capita income and regulatory efforts. T he analysis is disaggregated by source of emissions and demonstrates t hat population growth is strongly associated with some sources of emis sions but not with others. Thus, the overall impact of population grow th depends upon the composition of production and consumption activiti es in each county. I also explore whether the trend in number of house holds predicts better than the trend in number of persons, and whether the impact of population growth depends upon the age structure or sou rce of growth (immigration or domestic increase). Generally, these alt ernative specifications of population do not improve the models of atm ospheric emissions.