In the GAO report and others they cite the large pool of qualified or near qualified pilots who are ready to jump in as soon as the demand increases and wages (or other incentives) go up.

I am one of those people and am currently flying a desk making a very good wage, driving 20 minutes to work and back, and home every night for dinner.

While the pull of flying is strong to those of us diagnosed with the love of aviation from birth, I'm betting many others like myself have gotten pretty used to whatever lifestyle they eventually settled into. The longer they stay out, the harder it gets to give that up. Might not be as easy for us to fill the void as people think?

Just an example of how complex the question really is. There are lots of variables and individual stories behind all those numbers on spreadsheets...