First, a quick comment on Bloomberg symbols such as USGG10YR. These are actually yields on "generic bonds"; typically these are benchmark, on-the-run issues. Long story short, these are not zero coupon bond yields.
For fitted, constant maturity zero coupon rates or par yields, you've already compiled some of the major public sources. Here's a slightly augmented list for reference:
Free Sources
- United States: The Gurkaynak, Sack & Wright dataset, which represents off-the-run Treasury yields fitted using the Nelson-Siegel & Svensson models, go back to 1961. The Fed's H.15 release provides yields fitted to on-the-run issues using cublic splines, which also has a very long history.
- United Kingdom: Bank of England has fitted yields using a spline model going back to the 1970s.
- Canada: Bank of Canada publishes their fitted yields computed using the Merrill Lynch Exponential Spline model, with histories going back to the 1980s.
- Australia: This link and this one have RBA's fitted yields, also computed using the Merrill Lynch Exponential Spline Model.
- EMU: The ECB publishes fitted yields computed using the Svensson model, with histories going back to the start of Eurozone.
- Germany: Bundesbank's data is also computed using the Svensson model, with histories going back to the 1970s.
- Belgium: Here is the estimated yields published by National Bank of Belgium. History goes back to the early 1990s.
- Switzerland: SNB publishes zero coupon rates going back to 1988.
- China: ChinaBond has extensive fitted Chinese government yield curves since 2002, computed using a cubic Hermite spline if I remember correctly.
- Japan: Japan's Ministry of Finance has par yields for JGBs since 1974; these are calculated using a cubic spline as well.
- Norway: Norges Bank has the latest bond yields, although I'm not sure whether these are constant maturity yields.
- Russia: Bank of Russia publishes zero coupon rates, computed using the NS/Svensson-class models.
- Thailand: ThaiBMA publishes constant maturity bond yield, with history going back to 1999.
For completeness, there are a few additional links for benchmark yields (but not constant maturity yields):
Commercial Sources
- Augur Labs provides fitted zero coupon, par, and forward curves for 36 economies, with very long-term histories (typically 1970s for developed world and as far back as possible for EM economies). [Disclaimer: I'm affiliated with Augur Labs.]
- J.P. Morgan Markets has global fitted yield curves. This is "commercial" in the sense that it's not in the public domain, but the data is free for JP Morgan clients. The length of history is a bit uneven though, depending on the country of interest.
- Similar to Morgan Markets, Barclays Live provides many fitted yield curves to clients.
- ICE Index Platform also has pretty good global yield curves coverage (20+ countries and fairly decent history).
- Other providers are the usual suspect, such as Refinitiv, YieldBook, etc. I know they have such data, but I haven't used them for ages and can't say much about data quality/length.
