Monetary Policy

A central bank's core objective is price stability, most often stated as an explicit inflation target, usually pursued alongside a second goal such as supporting employment or stable growth. It pursues that objective mainly through one tool used every day: open market operations, buying or selling government securities to add or drain reserves from the banking system. A purchase injects reserves and pushes the policy rate down; a sale withdraws reserves and pushes it up. The discount rate mostly signals the bank's intended direction rather than doing the daily work, and reserve requirements are changed only rarely, because shifting them disrupts how banks manage their own liquidity.

A policy rate change reaches inflation only at the end of a chain, never directly. It first changes commercial lending rates. That changes the cost of borrowing for households and firms. That changes investment and consumption, then aggregate demand, and only then prices. Several channels carry this effect at once. The interest rate channel is the direct one. A credit channel runs through bank lending capacity. An exchange rate channel runs through the currency's value and net exports. An asset price channel runs through equity and property values feeding a wealth effect into consumption.

Whether that policy rate counts as expansionary or contractionary is judged against the neutral, or natural, rate, never against zero and never against last year's number. The neutral rate is the level consistent with stable inflation and output at its potential, neither pushing the economy forward nor holding it back. A policy rate below neutral is expansionary, whatever the number itself looks like; a rate above neutral is contractionary, even if that rate has just been cut. A central bank that lowers its rate from 4 percent to 3 percent while the neutral rate sits at 2 percent has still tightened policy relative to where it started, because the gap above neutral only narrowed, it did not close.

A central bank can commit to targeting inflation, an interest rate level, or an exchange rate, but not all three independently at the same time. Defending a fixed exchange rate requires following the anchor currency's own interest rate closely, which removes the freedom to set an independent domestic rate policy for other goals.

Two limitations define how far conventional monetary policy can reach. Near the zero lower bound, further rate cuts stop working. Nominal rates cannot fall much further, and money demand becomes highly elastic, so additional money supply is simply held rather than spent. This is the liquidity trap. Separately, policy works through three sequential lags. Recognition is noticing conditions have shifted. Response is deciding and implementing an action. Transmission is the change actually working its way through lending, spending and prices, and it is typically the longest of the three. That last lag creates a real risk: stimulus can land on an economy that has already turned around on its own.