25/9/2012: Some thoughts on US Government debt

There's much of a debate going on about which US President has added most to the US Government debt stockpile. The question is far from trivial.

Here's the chart plotting overall evolution of the US debt since 1980 with presidential tenures super-imposed onto it:

So far, it appears the contest is between Ronald Reagan, George W. Bush and Barack Obama. The tables below summarizes the presidential administrations' performance in terms of the US debt first in terms of absolute current US dollars and then in terms of debt to GDP ratios:

The problem is, of course, two-fold:

1. Presidential tenure starts in year 1, for which some of the budgetary dimensions are already Pre-set by the previous administration, and the tenure ends in year 4, when the outgoing President sets out some of the legacy measures for the incoming one;
2. Presidential tenures range between 4 and 8 years in the above period.

Controlling for the (1) is hard, so let's assume that the incoming President shares the burden of fiscal regime setting in year 1 with his predecessor. Tables below show this analysis:

The last two columns in the above summarize overall rates of change per year in office and this makes it clear:

• Current administration leads in terms of overall rate of increasing the US Government debt by a factor of 5 times that of the Reagan administration;
• The above does not account for inflation, as figures stated are in current US Dollars, but to match Barack Obama's rate of increasing public debt in real terms to that achieved by the Reagan administration we need annual inflation in excess of 6.5% pa. Meanwhile, over the period GDP deflator averaged 3.56%pa, while CPI averaged between 2.95% and 2.96% (depending on annual metric chosen);
• Obama administration also leads, by a massive margin, every other administration in the rates of debt increases relative to GDP.