I'm not starting this topic with the intention of rehashing a familiar a.net discussion, nor am I attempting to make a point about the effectiveness of EAS funding. I'm just seeking to understand something that I've never completely understood.
Can someone elaborate on the criteria as to why some airports are included in the eligibility for Essential Air Service, and others are not? Is it completely based upon whether an airport had commercial air service in 1978 when the industry was deregulated in the US? For example, Hot Springs, AR is an EAS airport, while Bowling Green, KY is not. Both are about the same size city, and are almost the exact same distance from a relatively major airport (LIT and BNA, respectively). I realize LIT doesn't have the same level of service as BNA, but it's still robust.
There are numerous other similar examples around the country that I could cite, but the key criteria appears to be that HOT had certificated commercial air service in 1978 and BWG did not (even though BWG appears to have had service briefly from Air Kentucky in the mid-1970s). Is that it? Or is there something else considered?