How To Easily Pay Down Debt

Whether in the global economy or your personal economy the picture shown here is true.  We as Certified Financial Planner Practitioners (tm) are regularly asked to make recommendations regarding college savings.  We also see student debt as liabilities for some clients years after entering the workplace.  It occurred to me how college debt could be compared to government debt as an example of how income growth makes paying down debt SO much easier.
(Gail Tverberg, actuary,source of the graphic above, http://ourfiniteworld.com.)

Let's look at three careers-- Teacher, Doctor and Plumber.  The teacher will earn $40,000 per year and borrowed $40,000 to get a degree.  The doctor will start at $150,000 per year and borrowed $150,000.  The plumber will start two years earlier than the teacher, 4 earlier than the doctor and have NO student debt.
               Gross        Minus payroll     Minus loan   Take-home
               pay/mo     deductions (30%)   payment*    pay
Teacher    $3,500       $1,050              $306          $2,144

Doctor      $12,500     $3,750               $1,147       $7,603

Plumber    $3,500       $1,050                   0           $2,450

*15 years 4.5% (This means they might have it paid off before their own children go to college.)

Looking at the Department of Labor's report on average household spending for 2013--at $40,000 income $2,000 per month is spent on food, clothing, shelter and transportation with a little in for entertainment and miscellaneous. That doesn't quite leave enough to pay the student loans for the teacher.  The plumber gets along just fine.

For the doctor--$5,000 per month is spent on the same stuff with nearly $1,500 per month left over to pay down the student debt faster if they want. 

WHAT DOES THIS MEAN FOR THE TITLE OF THE POST?

1. Borrowing lots of money to invest in a lucrative career is NOT a problem.  It becomes "easy" to pay it back and maybe even early.  
2. Borrowing lots of money to invest in a not so lucrative career IS a problem and makes it appear to be nearly impossible to pay it back.
3. Not going into debt, getting started early, AND going into a career that is stable albeit not so glamorous works well too.  

This is just like our country in this respect--it is MUCH easier to borrow money and pay it back when you invest it in an asset that will improve your chances of higher income down the road.  I did not include an example of someone who borrows $150,000 to get a job that pays $40,000 per year but we all know how that would go.  My concern with much of the current global economy is how detached it is from the real world and how much time, talent and treasure is being wasted on non-productive endeavors. 

If we were borrowing money to invest in improving the electric grid for example we could reap benefits for the rest of our lives.  If regulations were simplified to make business formations easier many people could be deployed in businesses that could increase our Gross Domestic Product much more efficiently.  

Any ideas?