I know in MA we have a huge problem with the lack of apprentices entering the trades. The average age of a plumber is 52, this is not a healthy average for my trade. At 36 I am the youngest in the company (10+ plumbers/heat techs). I have tried recruiting some young blood but I usually get some eye rolling and then disinterest after they learn that its a five year apprenticeship. Its seems that they would rather continue on complaining about about not having a good job for five years rather than sucking it up and put in the time for five to walk away with a license and a very large earning potential.Thankfully the U.S. economy is in an upswing and the jobs market here is looking better and better.
Crushing student debt is a problem, but I blame that on society pushing the notion that everyone needs to have at least a four year University degree (even if it's an essentially "useless" degree with little opportunity for employment) in order to be successful. There is nothing wrong with learning a trade and you can make excellent money in the trades.
I have heard that this is also a nation wide problem. What would the longer term impact would be in 10-20 years as more and more of the old timers retire? I think one of those trolls that hides in a dark closet, staring at economic data and drooling over the chart that its currently creating, could throw out a theory.