Investors value the liquidity and safety of US Treasuries. We document by showing that changes in Treasury supply have large effects on variety of yield spreads. As a result, Treasury yields are reduced by73 basis points, on average, from 1926 to 2008. Both the liquidity and attributes of Treasuries are driving this phenomenon. We document by analyzing the spread between assets with different liquidity (but similar safety) and those with different safety (but similar). The low yield on Treasuries due to their extreme safety and suggests that Treasuries in important respects are similar to.
Krishnamurthy et al. (Sun,) studied this question.