How Central Banks Fight Inflation: Monetary Policy Explained

The Institution Behind the Money#

Almost every country has a central bank — an institution responsible for issuing currency, overseeing the banking system, and managing monetary policy. The Federal Reserve in the United States, the Bank of England, the European Central Bank for the euro area, the Bank of Japan, the Swiss National Bank, the Reserve Bank of Australia, and the Central Bank of Brazil all perform broadly similar functions, though with important institutional differences.

A central bank is not an ordinary commercial bank. You cannot open a savings account with the Federal Reserve or apply for a mortgage from the Bank of England. Central banks are banks for banks — their customers are commercial banks, other central banks, and sometimes governments.

The Primary Tool: The Policy Interest Rate#

The most important lever a modern central bank pulls is the policy interest rate — the rate at which commercial banks can borrow from or park money with the central bank. This rate has many names: the federal funds rate (US), the Bank Rate (UK), the deposit facility rate (ECB), the uncollateralised overnight call rate (Japan).

When the policy rate changes, it propagates outward through the financial system. Commercial banks adjust the rates they charge each other. Mortgage rates shift. Corporate borrowing costs change. Saving rates change. Bond markets reprice. Currency markets react. Within weeks or months, the entire economy feels the adjustment.

The Mandate#

Central bank mandates vary by country. The European Central Bank's primary objective, under the EU treaties, is price stability, defined as inflation of 2% over the medium term. Other objectives are secondary. The US Federal Reserve's dual mandate includes both maximum employment and stable prices. The Bank of Japan has a 2% inflation target set by the government. The Bank of England's 2% inflation target is set annually by the Chancellor of the Exchequer.

These differences matter. During the 2008 financial crisis, the Fed's employment mandate gave it political cover to cut rates aggressively and pursue unconventional policies; the ECB, constrained by a narrower mandate, moved more slowly.

Example: During the euro-area crisis of 2011–2012, ECB President Mario Draghi famously declared the ECB would do "whatever it takes" to preserve the euro. This rhetorical intervention — backed by the later announcement of Outright Monetary Transactions — calmed bond markets without the ECB actually buying bonds under OMT. Central bank communication turned out to be a powerful tool in itself.

Independence#

Most modern central banks are politically independent. The government sets the inflation target; the central bank decides how to achieve it. This separation emerged in the 1990s as a response to the inflation of the 1970s and 1980s, when politicians were seen as too willing to cut rates before elections. New Zealand pioneered formal inflation targeting in 1989; the Bank of England gained operational independence in 1997; the Bank of Japan in 1998.

Independence is always contested. Elected politicians periodically criticise unelected central bankers — US President Donald Trump repeatedly attacked Fed Chair Jerome Powell during 2018–2020; Turkish President Erdoğan replaced three central bank governors in two years amid the 2019–2021 lira crisis; UK politicians have publicly sparred with Bank of England governors over both rate decisions and forecasts.