The E-GAS modeling system is a forecast model used to predict national and regional economic activity in order to estimate attainment of ozone and photochemical air quality standards. The report contains the E-GAS modeling system for EPA region 6. Since growth in source emissions largely depends on the amount of economic activity growth in an area, a consistent set of growth factors requires forecasts using consistent Gross National Product (GNP) forecasts and a consistent methodology for estimating economic activity in Urban Airshed Model (UAM) and Regional Oxidant Model (ROM) modeling regions. The need for consistent economic growth facts, however, must be satisfied in a way that allows States to use their own estimates of national and regional economic activity. The Economic Growth Analysis System (E-GAS) is an economic activity forecast model which satisfies both of these standards.