I don't know what to do with this

Graph #1: Two Measures of Interest on the Federal Debt. They can't both be right.

Two measures of interest on the federal debt:

• The blue one is https://fred.stlouisfed.org/series/A091RC1A027NBEA
  
• The red one is https://fred.stlouisfed.org/series/Y669RC1A027NBEA

It's not like one of them was discontinued. It's not an old version and a new version. It is two current versions. Two sets of books. If that's what they want to do, fine, but I want to know which one would be more useful to me. I want to know what they're leaving out of the one and including in the other. I find nothing on that.

If you look at the big number, the total Monetary Interest Paid data for all sectors including "Government: Federal", it starts at 1960 like the red one on the graph above. All the other components of the big number go back to 1946. It looks to me like they use the federal one that starts in 1960, our red one, when they figure the big number. And all the years before 1960 drop out of the picture.

Why use the federal measure that starts in 1960? I was assuming that it is the more recently created measure -- you know, the one they would say is more accurate. But now I'm not sure about that. I added one more series to the graph, the "current expenditures" version of federal government interest paid:

Graph #2

The new line (green) is a good match to the blue line and not the red. Green is quarterly data, blue is annual; this probably accounts for the small differences between these two. And the green one has the most current data of them all.

So I would say that of the three, the green one is the best one to use, the blue one is second best, and the red one is least worth using. And, since I find no information on the differences between red and blue, I can only confirm my opinion that the red one is the least worth using.

So you see, it doesn't make any sense to me that the red one is the one they use when they add up all the components of interest paid to get total interest paid. I'm at a loss here.

 

I know, this is not the kind of thing you usually find on the internet, when people talk about the interest on government debt. Can't be helped.