What is Interest rate and reasons for its change?

An interest rate is the rate at which interest is paid by a borrower for the use of money that they borrow from a lender. For example, a small company borrows capital from a bank to buy new assets for their business, and in return the lender receives interest at a predetermined interest rate for deferring the use of funds and instead lending it to the borrower. Interest rates are normally expressed as a percentage rate over the period of one year.

Interest rates targets are also a vital tool of monetary policy and are taken into account when dealing with variables like investment, inflation, and unemployment.

Reasons for interest rate change

• Political short-term gain: Lowering interest rates can give the economy a short-run boost. Under normal conditions, most economists think a cut in interest rates will only give a short term gain in economic activity that will soon be offset by inflation. The quick boost can influence elections. Most economists advocate independent central banks to limit the influence of politics on interest rates.
• Deferred consumption: When money is loaned the lender delays spending the money on consumption goods. Since according to time preference theory people prefer goods now to goods later, in a free market there will be a positive interest rate.
• Inflationary expectations: Most economies generally exhibit inflation, meaning a given amount of money buys fewer goods in the future than it will now. The borrower needs to compensate the lender for this.
• Alternative investments: The lender has a choice between using his money in different investments. If he chooses one, he forgoes the returns from all the others. Different investments effectively compete for funds.
• Risks of investment: There is always a risk that the borrower will go bankrupt, abscond, die, or otherwise default on the loan. This means that a lender generally charges a risk premium to ensure that, across his investments, he is compensated for those that fail.
• Liquidity preference: People prefer to have their resources available in a form that can immediately be exchanged, rather than a form that takes time or money to realise.
• Taxes: Because some of the gains from interest may be subject to taxes, the lender may insist on a higher rate to make up for this loss.

Real vs nominal interest rates

The nominal interest rate is the amount, in money terms, of interest payable.

For example, suppose a household deposits $100 with a bank for 1 year and they receive interest of $10. At the end of the year their balance is $110. In this case, the nominal interest rate is 10% per annum.

The real interest rate, which measures the purchasing power of interest receipts, is calculated by adjusting the nominal rate charged to take inflation into account. (See real vs. nominal in economics.)

If inflation in the economy has been 10% in the year, then the $110 in the account at the end of the year buys the same amount as the $100 did a year ago. The real interest rate, in this case, is zero.

After the fact, the ‘realized’ real interest rate, which has actually occurred, is given by the Fisher equation, and is

where p = the actual inflation rate over the year. The linear approximation

is widely used.

The expected real returns on an investment, before it is made, are:

where:

= nominal interest rate

= real interest rate

= expected or projected inflation over the year

Market interest rates

There is a market for investments which ultimately includes the money market, bond market, stock market and currency market as well as retail financial institutions like banks.

Exactly how these markets function is a complex question. However, economists generally agree that the interest rates yielded by any investment take into account:

• The risk-free cost of capital
• Inflationary expectations
• The level of risk in the investment
• The costs of the transaction

This rate incorporates the deferred consumption and alternative investments elements of interest.

Inflationary expectations

According to the theory of rational expectations, people form an expectation of what will happen to inflation in the future. They then ensure that they offer or ask a nominal interest rate that means they have the appropriate real interest rate on their investment.

This is given by the formula:

where:

= offered nominal interest rate

= desired real interest rate

= inflationary expectations

Risk

The level of risk in investments is taken into consideration. This is why very volatile investments like shares and junk bonds have higher returns than safer ones like government bonds.

The extra interest charged on a risky investment is the risk premium. The required risk premium is dependent on the risk preferences of the lender.

If an investment is 50% likely to go bankrupt, a risk-neutral lender will require their returns to double. So for an investment normally returning $100 they would require $200 back. A risk-averse lender would require more than $200 back and a risk-loving lender less than $200. Evidence suggests that most lenders are in fact risk-averse.

Generally speaking a longer-term investment carries a maturity risk premium, because long-term loans are exposed to more risk of default during their duration.

A market interest-rate model

A basic interest rate pricing model for an asset

Assuming perfect information, p_e is the same for all participants in the market, and this is identical to:

where

i_n is the nominal interest rate on a given investment

i_r is the risk-free return to capital

i*_n = the nominal interest rate on a short-term risk-free liquid bond (such as U.S. Treasury Bills).

rp = a risk premium reflecting the length of the investment and the likelihood the borrower will default

lp = liquidity premium (reflecting the perceived difficulty of converting the asset into money and thus into goods).

Negative interest rates

Interest rates are usually positive, but not always. Given the alternative of holding cash (thus earning 0%) rather than lending it out, profit-seeking lenders will not lend below 0%, as that will guarantee a loss, and a bank offering a negative deposit rate will find few takers, as savers will instead hold cash.

However, central bank rates can be negative; in July 2009 Sweden’s Riksbank was the first central bank to use negative interest rates, lowering its deposit rate to −0.25%, a policy advocated by deputy governor Lars E. O. Svensson. This negative interest rate is possible because Swedish banks, as regulated companies, must hold these reserves with the central bank – they do not have the option of holding cash.

Negative interest rates have been proposed in the past, notably in the late 19th century by Silvio Gesell. A negative interest rate can be described (as by Gesell) as a "tax on holding money"; he proposed it as the Freigeld (free money) component of his Freiwirtschaft (free economy) system. To prevent people from holding cash (and thus earning 0%), Gesell suggested issuing money for a limited duration, after which it must be exchanged for new bills – attempts to hold money thus result in it expiring and becoming worthless