interesting thread. Firstly, I fully agree with those on a disciplined asset allocation plan. It is best to stick with it and avoid market timing.
For me, i'm currently revising my AA plan (at the point of FIRE) and have been studying/considering investing more into bonds for income and lower risk profile. So this is very much on my mind. I am also concerned about rising rates in US this year and the unknown effects of unconventional policies by many central banks.
I just found this Buffett quote in another thread : "Today, a wry comment that Wall Streeter Shelby Cullom Davis made long ago seems apt: “Bonds promoted as offering risk-free returns are now priced to deliver return-free risk.” " - Feb 2012.
I think the situation can only have amplified in the subsequent 3 years since he wrote that.
Luckily for me as an Australian investor, cash interest rates (can get 3.5 to 4% if you hunt around) are not too bad and historically can be at a premium to bond yields. Therefore at the current time I'm inclined to keep my defensive allocation substantially in cash, only a small portion Aust gov bonds and an even smaller portion in International bonds. I will re-assess to add more bonds for steady income in some years time, after central bank balance sheets and bond yields are more "normalized" (if and when that ever occurs!).