There will never be a pilot shortage. The way of recruiting though might have to undergo a transformation. For years the typical model for an airline pilot was a two track system. Either you went to the military or you got your ratings started flight instructing and then moved up to a regional carrier. This system will most likely not work in the future. The Europeans for decades have had a Cadet pilot system in place. This is now becoming the normal mode of pilot recruiting in Asia and the Middle East. At my current airline in Asia the new Cadet pilots are recruited after college if the can pass the medical. Not easy as it is a 50% failure rate. Those successful applicants are then sent to the states for 1 year to go from zero hours to fully rated ME pilots and 250 hours TT. They then proceed back to Asia and do 3 months of intensive ground school and simulator training. The next step is 3 months of jumpseating and observation flights. They then begin their actual B-737 NG flight training and FO checkout. After 4 years they upgrade to Captain. There is not nor will there ever be a pilot shortage. The model is changing and the US carriers may have to adapt to a cadet pilot system as the rest of the world is now utilizing.