Passenger demand shows a measurable link to the local economy at medium-hub and non-hub airports only. At large and small hubs the estimate is too imprecise to say anything.
What this shows: The chart plots GDP elasticity and Carrier elasticity on a vertical axis of Elasticity.
Conditions and method
Status: descriptive (significance varies by driver in this model; only some rows are statistically distinguishable from zero).
2 of 4 tier GDP elasticities are not identified: a test cannot tell them from zero at the 5% level. Each airport is in the tier it held in 2004, the last complete year before the window; 21 airports with no tier that year are left out. The carrier elasticity plotted beside it comes from a separate regression, because the number of carriers at an airport is determined together with its passengers.