AB Bernstein came up with the calculation — 1,832%, to be exact — by including not only traditional levels of public debt like bonds but also financial debt and all its complexities as well as future obligations for so-called entitlement programs like Social Security, Medicare and public pensions.

Putting all that together paints a daunting picture but one that requires nuance to understand. Paramount is realizing that not all of the debt obligations are set in stone, and it's important to know where the leeway is, particularly in the government programs that can be changed either by legislation or accounting.