The banks in effect borrow cash and must pay it back; the short durations allow interest rates to be adjusted continually. When the repo notes come due the participating banks bid again. An increase in the quantity of notes offered at auction allows an increase in liquidity in the economy. A decrease has the contrary effect. The contracts are carried on the asset side of the European Central Bank's balance sheet and the resulting deposits in member banks are carried as a liability. In layman terms, the liability of the central bank is money, and an increase in deposits in member banks, carried as a liability by the central bank, means that more money has been put into the economy.[a]