Query on Measuring of consumer debt

[Carrol Cox]

How do they calculate that part of credit card debt that is paid off at
the end of every month? The only time in 30 years of using credit cards
that I ever paid any interest was once when the envelope carrying the
payment slipped down between the car seat and the passenger door and only
showed up about 3 weeks later. Yet there have been times when, for the
period between making the charge and the arrival of the bill my balance
would have been very high. I presume this practice accounts for some
substantial proportion of credit card debt, but is it really debt?

Carrol