I don't know if it's still true, but when we were doing a analysis of alternatives for a customer looking to modernize, we reviewed salary surveys to determine

I don't know if it's still true, but when we were doing a analysis of alternatives for a customer looking to modernize, we reviewed salary surveys to determine the future cost of maintenance. While COBOL developers were about 15% cheaper than Java developers, our concern is that (long term) it would dis-incentivize developers from learning COBOL.