Using the re-issuance policy of the French Treasury, we show that issuances of long-term debt (bonds) increase yields four times as much as issuances of short-term debt (bills). Surprisingly, the modest price impact of bills is not due to differences in secondary market liquidity or the dash for cash during crises. Duration alone cannot explain the higher price impact of bond issuances. The different properties of bills and bonds stem from preferred habitat investors who need time to absorb additional bond issuance compared to the elastic demand of foreign investors for bills. Governments thus rely on bills when they need cash quickly.