This paper examines the effect of monetary policy on the liquidity premium, i.e., the market value of the liquidity services that financial assets provide. To guide the empirical analysis, I set up a monetary search model in which bonds provide liquidity services in addition to money. The theory predicts that money supply and the nominal interest rate are positively correlated with the liquidity premium, but the latter is negatively correlated with the bond supply. The empirical analysis over the period from 1946 and 2008 confirms the theoretical findings. This indicates that liquid bonds are substantive substitutes for money and the opportunity cost of holding money plays a key role in asset price determination. The model can rationalize ...