Before Y2K this was a factor. Now days security sensitivities have driven the work back home.

According to my old COBOL professor, it's notoriously hard to outsource COBOL development. Apparently Americans were the first and (for the most part) only to rely on big iron so much to need mainframes.

Side note: I had my class in COBOL in 2005, my dad took it in roughly 1975.