There cannot simultaneously be a surplus of COBOL developers and a shortage of COBOL developers.

Well, supposedly there could be one in the Midwest and one in NJ, but theoretically those who do not have a job in the Midwest would be motivated to move, since their only options are:

A) Remain jobless in Midwest.

B) Switch careers in Midwest.

C) Move to NJ for immediately available position.

The bigger question is why does a COBOL dev accept work for 60k when they could make 120k in Javascript?