The Rule of 70 can help us understand the effects of compounding:
II. Productivity: Its Role and Determinants
A. Why Productivity Is So Important
1. Example: Robinson Crusoe
a. Because he is stranded alone, he must catch his own fish, grow his own vegetables, and make his own clothes.
Rule of 70: If a variable grows at X% per year,then
that variable will double in approximately 70 / X years.