As they say, somethings are so silly on the highly educated can believe them. John Campbell, an archetype of conventional financial academic thinking, has an interesting yet absurd piece on why the low yields of US treasuries makes sense. He starts off with the standard view, that yields of government bonds are due to three things
- expected real interest rates
- expected inflation
- risk premium
As current interest rates are around 2.5%, and current inflation expectations are around 3%, even with a slight convexity adjustment there's a negative real expected return here. To guys like Campbell, that means, bonds are some kind of insurance, because the only reason investors would accept this is if they pay off in a very bad state of nature, just as you pay for car insurance. Specifically, everyone is suposedly afraid of a recession that would also bring with it deflation.
While the CAPM betas of bonds have historically been positive, they have been negative lately. If you believed in the CAPM, that would mean the expected negative return makes sense, it is a negative 'risk premium'. Of course, the positive beta previously did not explain why bonds cratered from 1960 to 1980, and the CAPM does not work at all within equities, the arena it was designed for. It also does not work in corporate bonds, REITs, options, etc. But looked at in isolation it is a plausible explanation, and hope springs eternal.
I think a better explanation of the current interest rates is that the Federal Reserve has been buying hundreds of billions of dollars in US Treasuries. Considering, they have an infinite supply of capital to do this (they create the money when they write the check), the market is not going to offset this via expectations of future inflation. So, the expectations are there, but US Treasuries are a rigged market, with one huge buyer debasing the world's most powerful currency because it's in the standard Keynesian manual for how to treat excess unemployment when inflation is currently low. Once the evidence of this short-sighted policy becomes clear, the inflation toothpaste will be out of the tube, and on to the next bubble-crash.
That is, the expected return on bonds is negative, because bonds are in a Fed-supported bubble. Just look at gold to see what an inflation sensitive market looks like without Fed shenanigans. US Treasuries are not insurance any more than tech stocks were insurance in 1999.