Sterilization Operations

Sterilization Operations are central bank interventions that neutralize the monetary impact of foreign exchange market operations, maintaining domestic money supply while influencing exchange rates. When central banks buy foreign currency to weaken their own currency, they inject domestic money into circulation. Sterilization involves offsetting this through open market operations – selling government securities to absorb the excess liquidity. For example, when the Swiss National Bank intervened to weaken the franc in 2011-2015, it sterilized by issuing SNB bills and increasing minimum reserve requirements. China regularly sterilizes its foreign exchange interventions through reserve requirement adjustments and central bank bill issuance. Without sterilization, forex interventions would cause inflation (when buying foreign currency) or deflation (when selling). However, sterilization has costs – the central bank typically earns less on foreign reserves than it pays on sterilization instruments, creating quasi-fiscal costs. The effectiveness of sterilized intervention remains debated, as it may signal policy intentions but doesn’t fundamentally alter money supply or interest rates.