Turns out, the "GS10" identification used for Robert Shiller's interest rate data is a FRED identification. Graph #1 shows monthly and annual patterns of FRED's GS10:
|Graph #1: FRED GS10 Interest, Monthly (blue) & Annual (red)|
I took the Shiller interest-rate numbers and condensed them to the January values only, for all the years in the Shiller file. Then I took annual values from the FRED GS10 as well. I combined the FRED numbers with Shiller's on the same graph. Graph #2 shows these together, since 1950:
|Graph #2: Shiller Januaries (blue) & FRED GS10 Annual (red)|
It's a toss-up. I guess you could even argue that Shiller's annual numbers (blue on Graph #2) look more like FRED's monthly values (blue on Graph #1) than FRED's annuals do.
I'll use the Shiller January numbers for the DPD comparison.