TRB's Airport Cooperative Research Program (ACRP) Synthesis 7: Airport Economic Impact Methods and Models explores how airport economic impact studies are currently conducted.  The report examines the methods and models used to define and identify, evaluate and measure, and communicate the different facets of the economic impact of airports.  The report also highlights the various analysis methods, models, and tools that are available for local airport economic studies, as well as their applicability and tradeoffs, including limitations, trends, and recent developments.