Inflation and Consumer Spending
Purchasing Power
Purchasing power is the amount of goods or services that can be purchased with a unit of currency. For example, if you had taken one dollar to a store in the 1950s, you would have been able to buy a greater number of items than you would today, indicating that you would have had a greater purchasing power in the 1950s. Currency can be either a commodity money, like gold or silver, or fiat currency, or free-floating market-valued currency like US dollars. As Adam Smith noted, having money gives one the ability to "command" others' labor, so purchasing power to some extent is power over other people, to the extent that they are willing to trade their labor or goods for money or currency.
If one's monetary income stays the same, but the price level increases, the purchasing power of that income falls. Inflation does not always imply falling purchasing power of one's money income since it may rise faster than the price level. A higher real income means a higher purchasing power since real income refers to the income adjusted for inflation.