The Pareto Principle is named after a 19th Century economist named Vilfredo Pareto. He noticed that most of the wealth in Italy was owned by a small number of people. He used his observation to create a mathematical rule which is now called the Pareto Principle. The Pareto Principle states that 80% of the effects come from 20% of the causes. This means that often in life, a small number of things are responsible for most of the results. This idea can be applied in all sorts of areas, like business, where 80% of your profits could come from 20% of your customers, or in your personal life, where you might find that 80% of your happiness comes from 20% of your activities.