Inflation is defined as a persistent increase in general price level. Inflation is measured by the proportional changes over time in some appropriate price index, commonly a consumer price index. General Price level refers to an average of all price in an economy and changes in reflect in the cost of living.
Inflation however affects many thing one being function of money such as medium of exchange, store of value, unit of account and standard of deferred payments.
Medium of exchange means that any item that is widely acceptable in exchange of goods and services.
The existence of a medium allows trade to take place without the need for a joint coincidence of wants. A medium of exchange facilitates economic transactions. As long as the same money is going to be accepted as payment, inflation will not affect this function. But in extreme cases of inflation, people may lose confidence in money to the extent that they don’t trust it, and resort to barter or some other means of conducting transactions.
Another function of money is store of value. If asset prices are stable, money is unattractive as a store of value, as it brings in no income, but if asset prices are unstable it may be worth holding some part of total assets in money, as a safeguard against risk. This is the one that inflation obviously affects the most. Inflation erodes the value of money; it does not keep its value. Something that costs a certain amount today will cost more tomorrow. This affects everything from the timing of transactions to the amount required for future payments (interest rates).
One of the roles of money is to be the unit of account in which contracts are expressed and individual incomes or firms’ profits are measured. High and fluctuating rates of inflation interfere with the performance of money as a unit of account, which is believed to be bad for the efficiency and equitable running of the economy. Inflation affects this function in two ways: different prices change by different amounts during inflation, making comparisons difficult, and unstable prices makes it difficult for people to have perfect information for comparisons.
Inflation also affects another function of money known as standard of deferred payments. Standard of deferred payments means that a contract or agreement may specify (or imply) that the repayment of a debt be made using a particular monetary unit. It differs from other functions of money in that it is not functioning as an immediate medium of exchange or store of value but, rather, as a medium by which future payments will be made.
Deferred payments depend in part on price and the unit of account function of money, and in part on how well money stores value. This means that deferred payments depend on interest rates and inflation. In the preceding car-buying example, Duncan Thurly is unlikely to purchase a car with deferred payments that total ONLY $10,000. Suppose, for example, that Duncan plans to make one deferred payment a year after purchasing his $10,000 car. If the going interest rate is 10 percent, then Duncan’s deferred payment is something like $11,000.
The extra $1,000 (10 percent of the $10,000 price) is needed to compensate the seller for the interest lost when waiting a year to get paid. This 10 percent interest adjustment of the deferred payment is also dependent on inflation. A positive inflation rate (anything greater than zero) means that the interest rate is greater than 10 percent.
That is, the seller also needs to be compensated for the loss of value resulting from higher prices. Alternatively, a negative inflation rate (anything less than zero) means that the interest rate is less than 10 percent. A 5 percent annual inflation rate means that the deferred payment for this $10,000 car is approximately $11,500. This amount is the combination of the $10,000 purchase price, the $1,000 interest, and an extra $500 to adjust for the declining value of the money resulting from higher prices.