Negative interest on excess reserves

Negative interest on excess reserves is an instrument of unconventional monetary policy applied by central banks to encourage lending by making it costly for commercial banks to hold their excess reserves at central banks so they will lend more readily to the private sector. Such a policy is usually a response to very slow economic growth, deflation, and deleveraging.

During economic downturns, central banks often lower interest rates to stimulate growth. Until late in the 20th century, it was thought that rates could not go below zero because banks would hold onto cash instead of paying a fee to deposit it. It turns out this was not quite right. Central banks in Europe and in Japan have demonstrated rates can go negative, and several have pushed them in that direction for the same reason they lowered them to zero in the first place—to provide stimulus and, where inflation is below target, to raise the inflation rate. The notion is that negative rates will provide even more incentive for commercial banks to make loans. What might have looked like a potential lending project, by a bank, not worth funding even in a low-interest-rate environment might now look attractive if the alternative is being charged to store money at the central bank or holding a large amount of cash.