Rule of 70 ( estimating the time for money's buying power to halve)

Description

Purchasing power (sometimes retroactively called adjusted for inflation) is the number of goods or services that can be purchased with a unit of currency. In economics, inflation is a sustained increase in the general price level of goods and services in an economy over a period of time. To determine approximately the time for money’s buying power to halve, financiers simply divide the rule-quantity by the inflation rate.