If central banks increase the money supply too quickly, it can cause inflation. This happens when there is increased money but only a fixed amount of goods available for sale when the money supply increases. A central bank is an independent organization responsible for monetary policy, and is considered independent from the government. This means that while a central bank can give additional funds to banks, they can't force the banks to lend this money to individuals and businesses. If this money does not end up in the hands of consumers, the lending to the banks will not impact the money supply, and therefore will be ineffective at stimulating the economy. Another potentially negative consequence is that quantitative easing generally causes a depreciation in the value of the home country's currency. Depending on the country, this can be a negative. It is good for a country's exports, but bad for imports, and can result in the country's residents having to pay more money for imported goods.