Columbia subject headings:
Aeronautics, Commercial--Economic aspects--United States.
Airlines--United States--Forecasting.
Economic forecasting--United States.
United States--Economic policy--2001-
Harvard subject headings:
Aeronautics, Commercial--Economic aspects--United States.
Airlines--United States--Forecasting.
Economic forecasting--United States.
United States--Economic policy--2001-2009.
Princeton subject headings:
Aeronautics, Commercial--Economic aspects--United States.
Airlines--United States--Forecasting.
Economic forecasting--United States.
United States--Economic policy--2001-2009.