In all fairness to Fence, I get the impression from reading these message boards that pilots who are not bred within the U.S. aviation scene have no clue that the entire process is different here.
In the U.S. novice pilots usually start with the goal of getting hired by a major U.S. carrier. Every step of progress in our early careers is done with that goal in mind. Once achieved, we are more attached to that particular carrier than we are to our own eye color. This can be a good thing; it can be a very bad thing, also.
With extremely rare exception, no one leaves a position with a major U.S. carrier to start elsewhere, and this is how the U.S. scene differs from the international piloting scene. Reading some of these boards it appears that pilots who go expat to fly will change carriers for a plethora of reasons. It is a workable solution in that realm. Some carriers hire direct entry captains and an experienced pilot can move with impunity from carrier to carrier, country to country, and keep compensation and seats fairly stable. THAT doesn't happen in the U.S. Unless one jumps on with a VERY RARE startup carrier, there are no direct entry captains in the U.S. Every pilots starts at the very bottom of the heap.
You may have 8,000 hours of 747 captain time at BA. When Continental calls it will be for a F/O position behind about 5,000 other pilots on their seniority list. The pay and scheduling (rosters) will be the exact same thing that they offer to 2,000-hour Navajo jockeys who are also looking for work. That will be the only thing offered, and the offer will be exactly the same at Delta, Northwest, Southwest, American, United, USAirways, etc. I have well over 10,000 hours of captain (including wide-body international) time at a major U.S. carrier. If I wanted to work at another U.S. carrier, I would also be offered the bottom F/O position along with the 2,000-hour Navajo jockeys.
There is NO lateral movement for pilots within the airline industry in the United States. And there are no (repeat: NO) D.E.C. positions at major carriers, either. It just does not work that way here.