This study estimates the economic impacts of current and future Marcellus development activity. Natural gas development stimulates the economy through business-to-business spending and via payments to land owners. Natural gas development involves exploration, drilling, building gas processing plants, and pipeline construction. Each of these activities requires goods and services from many sectors of the economy, including construction, truck transportation, iron and steel, and engineering construction services. Natural gas companies also pay lease and royalty payments to land owners, who in turn pay taxes and spend this income on goods and services.