If you asked virtually any banker or economist a few years ago whether negative (nominal) interest rates were possible, the answer would almost certainly be no.
Negative real interest rates have been common at many points in time – whenever the rate of inflation exceeds the nominal rate of interest. People’s debts and savings are eroded by inflation as the interest due or earned does not keep pace with rising prices.
But negative nominal rates? Surely this could never happen? It was generally believed that zero (or slightly above zero) nominal rates represented a floor – ‘a zero lower bound’.
The reasoning was that if there were negative nominal rates on borrowing, you would effectively be paid by the bank to borrow.
In such a case, you might as well borrow as much as you can, as you would owe less later and could pocket the difference.
A similar argument was used with savings. If nominal rates were negative, savers might as well withdraw all their savings from bank accounts and hold them as cash (perhaps needing first to buy a safe!) Given, however, that this might be inconvenient and potentially costly, some people may be prepared to pay banks for looking after their savings.
Central bank interest rates have been hovering just above zero since the financial crisis of 2008. And now, some of the rates have turned negative (see chart above). The ECB has three official rates:
| • | The interest rate on the main refinancing operations (MRO), which provide the bulk of liquidity to the banking system. |
| • | The rate on the deposit facility, which banks may use to make overnight deposits with the Eurosystem. |
| • | The rate on the marginal lending facility, which offers overnight credit to banks from the Eurosystem. |
The first of these is the most important rate and remains above zero – just. Since September 2014, it has been 0.05%. This rate is equivalent to the Bank of England’s Bank Rate (currently still 0.5%) and the Fed’s Federal Funds Rate (currently still between 0% and 0.25%).
The third of the ECB’s rates is currently 0.3%, but the second – the rate on overnight deposits in the ECB by banks in the eurozone – is currently –0.2%. 
In other words, banks have to pay the ECB for making these overnight deposits (deposits that can be continuously rolled over). The idea has been to encourage banks to lend rather than simply keeping unused liquidity.
In Nordic countries, the experiment with negative rates has gone further. With plenty of slack in the Swedish economy, negative inflation and an appreciating krona, the Swedish central bank – the Riksbank – cut its rates below zero.
Many City analysts believe that the Riksbank will continue cutting, reducing its key interest rate to minus 0.5% by the end of the year [it is currently 0.35%]. Switzerland’s is already deeper still, at minus 0.75%, while Denmark and the eurozone have joined them as members of the negative zone.
But the nominal interest rate on holding cash is, by definition, zero. If deposit rates are pushed below zero, then will more and more people hold cash instead? 
The hope is that negative nominal interest rates on bank accounts will encourage people to spend. It might, however, merely encourage them to hoard cash.
The article below from The Telegraph looks at some of the implications of an era of negative rates. The demand for holding cash has been increasing in many countries and, along with it, the supply of banknotes, as the chart in the article shows. Here negative interest are less effective. In Nordic countries, however, the use of cash is virtually disappearing. Here negative interest rates are likely to be more effective in boosting aggregate demand.
Article
How Sweden’s negative interest rates experiment has turned economics on its head The Telegraph, Peter Spence (27/9/15)
Data
Central bank and monetary authority websites Bank for International Settlements
Central banks – summary of current interest rates global-rates.com
Questions
- Distinguish between negative real and negative nominal interest rates.
- What is the opportunity cost of holding cash – the real or the nominal interest rate forgone by not holding it in a bank?
- Are there any dangers of central banks setting negative interest rates?
- Why may negative interest rates be more effective in Sweden than in the UK?
- ‘Andy Haldane, a member of the Monetary Policy Committee (MPC) … suggested that to achieve properly negative rates, the abolition of cash itself might be necessary.’ Why?
- Why does Switzerland have notes of SF1000 and the eurozone of €500? Should the UK have notes of £100 or even £500?
- Why do some banks charge zero interest rates on credit cards for a period of time to people who transfer their balances from another card? Is there any incentive for banks to cut interest rates on credit cards below zero?