When there is an increased demand for base money, the central bank must act if it wishes to maintain the short-term interest rate. It does this by increasing the supply of base money: it goes to the open market to buy a financial asset, such as government bonds. To pay for these assets, new central bank money is generated in the seller's loro account, increasing the total amount of base money in the economy. Conversely, if the central bank sells these assets in the open market, the base money is reduced.