Just a brief followup on this post, addressing a topic raised briefly at the end of it, which was a question as to why US debt grows faster than the annual deficits.

The table can be found here at US Debt vs Deficit table, 1929-2020, of which a partial section (2007-2020) is taken.

As you can see, the annual increase in debt is not linked directly to the annual deficit. Even in years like 2000 and 2001 when the US ran (technical) surpluses, the debt still increased.

There are a number of reasons for this, but this is a big one.

The deficit has been less than the increase in the debt because Congress began borrowing from the Social Security Trust Fund surplus in 1987. The surplus was created by the baby boomer generation. They contributed more because there were more working people than retirees during their peak working years.7

Their payroll tax contributions were greater than Social Security spending. That allowed the fund to invest the extra revenue in special Treasury bonds. Congress spent some of the surplus so that it wouldn’t have to issue as many new Treasury notes. 

Both Social Security and Medicare/Medicaid are going to go into the red in the next few years so that source of “borrowing” will vanish.

But what it really comes down to is that the US has simply deliberately decided to not pay down the debt, instead rolling much of it over as interest rates dropped to zero or near-zero. That will not be the case forever, which means this chart cannot go as it has.

Ha! In searching through my bookmarked articles I came across this gem from 2011.